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Count pairs with given sum - #10282

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cclauss merged 23 commits into
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siddwarr:count_pairs_with_given_sum
Oct 12, 2023
Merged

Count pairs with given sum#10282
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum

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@siddwarr

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Describe your change:

I have added the solution to the problem for counting the no of pairs in an array with the given sum in the most optimal way

  • Add an algorithm?
  • Fix a bug or typo in an existing algorithm?
  • Documentation change?

Checklist:

  • I have read CONTRIBUTING.md.
  • This pull request is all my own work -- I have not plagiarized.
  • I know that pull requests will not be merged if they fail the automated tests.
  • This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
  • All new Python files are placed inside an existing directory.
  • All filenames are in all lowercase characters with no spaces or dashes.
  • All functions and variable names follow Python naming conventions.
  • All function parameters and return values are annotated with Python type hints.
  • All functions have doctests that pass the automated testing.
  • All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
  • If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

@algorithms-keeperalgorithms-keeperBot added the awaiting reviews This PR is ready to be reviewed label Oct 11, 2023
@cclauss

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I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

>>> pairs_with_sum([1,7,6,2,5,4,3,1,9,8],7)
4
"""
d: dict = {}

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Suggested change
d: dict= {}
d= {}

This type is inferred. Also try to use more descriptive variable names

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So I had to add that because it wasn't passing all the three tasks. I know we don't have to mention the type but I did so just to pass all the three tasks

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It gave some type not specified error

d[i] -= 1
if req_sum - i in d and d[req_sum - i] != 0:
ans += d[req_sum - i]
d[i] += 1

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You are subtracting one, and then adding one after an irrelevant if statement. Why?

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So the reason I included that is because let's say the given number is 8 and you have 4 in your array. Now if u don't decrement d[4] by 1 then from the code it will check if 4 exists in the dictionary and as it does ans will be incremented. So even though there is only one 4 in the array it will still be considered. I could remove that and put if d[req-i]!=1

@siddwarr

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I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

This is the solution to an array leetcode problem. Yes you can use defaultdict for the first half. I just thought this will be more descriptive and easier to comprehend. I can change that. I think this problem is good for beginners to understand why hashing is required for these types of array questions

@cclauss

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This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

@algorithms-keeperalgorithms-keeperBot added the tests are failing Do not merge until tests pass label Oct 12, 2023
@siddwarr

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This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

@siddwarr

Copy link
Copy Markdown
ContributorAuthor

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.
Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.
If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

I have added the problem link in the docstring

Comment on lines +6 to +7
Count the no of pairs in a given array with given sum
Problem URL- https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

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Suggested change
Countthenoofpairsinagivenarraywithgivensum
ProblemURL-https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0
Givenanarrayofintegersandanintegerreq_sum, findthenumberofpairsofarray
elementswhosesumisequaltoreq_sum.
https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

@algorithms-keeperalgorithms-keeperBot removed the tests are failing Do not merge until tests pass label Oct 12, 2023
Comment threaddata_structures/arrays/pairs_with_given_sum.py Outdated
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss disabled auto-merge October 12, 2023 09:08
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss merged commit 09ce6b2 into TheAlgorithms:masterOct 12, 2023
@algorithms-keeperalgorithms-keeperBot removed the awaiting reviews This PR is ready to be reviewed label Oct 12, 2023
@siddwarr
siddwarr deleted the count_pairs_with_given_sum branch October 12, 2023 10:12
@isidroasisidroas mentioned this pull request Jan 25, 2025
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@siddwarr@cclauss@CaedenPH
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Count pairs with given sum by siddwarr · Pull Request #10282 · TheAlgorithms/Python · GitHub
Skip to content

Count pairs with given sum - #10282

Merged
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum
Oct 12, 2023
Merged

Count pairs with given sum#10282
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum

Conversation

@siddwarr

Copy link
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Contributor

Describe your change:

I have added the solution to the problem for counting the no of pairs in an array with the given sum in the most optimal way

  • Add an algorithm?
  • Fix a bug or typo in an existing algorithm?
  • Documentation change?

Checklist:

  • I have read CONTRIBUTING.md.
  • This pull request is all my own work -- I have not plagiarized.
  • I know that pull requests will not be merged if they fail the automated tests.
  • This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
  • All new Python files are placed inside an existing directory.
  • All filenames are in all lowercase characters with no spaces or dashes.
  • All functions and variable names follow Python naming conventions.
  • All function parameters and return values are annotated with Python type hints.
  • All functions have doctests that pass the automated testing.
  • All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
  • If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

@algorithms-keeperalgorithms-keeperBot added the awaiting reviews This PR is ready to be reviewed label Oct 11, 2023
@cclauss

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I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

>>> pairs_with_sum([1,7,6,2,5,4,3,1,9,8],7)
4
"""
d: dict = {}

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Suggested change
d: dict= {}
d= {}

This type is inferred. Also try to use more descriptive variable names

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ContributorAuthor

Choose a reason for hiding this comment

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So I had to add that because it wasn't passing all the three tasks. I know we don't have to mention the type but I did so just to pass all the three tasks

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ContributorAuthor

Choose a reason for hiding this comment

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It gave some type not specified error

d[i] -= 1
if req_sum - i in d and d[req_sum - i] != 0:
ans += d[req_sum - i]
d[i] += 1

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

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You are subtracting one, and then adding one after an irrelevant if statement. Why?

Copy link
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ContributorAuthor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

So the reason I included that is because let's say the given number is 8 and you have 4 in your array. Now if u don't decrement d[4] by 1 then from the code it will check if 4 exists in the dictionary and as it does ans will be incremented. So even though there is only one 4 in the array it will still be considered. I could remove that and put if d[req-i]!=1

@siddwarr

Copy link
Copy Markdown
ContributorAuthor

I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

This is the solution to an array leetcode problem. Yes you can use defaultdict for the first half. I just thought this will be more descriptive and easier to comprehend. I can change that. I think this problem is good for beginners to understand why hashing is required for these types of array questions

@cclauss

Copy link
Copy Markdown
Member

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

@algorithms-keeperalgorithms-keeperBot added the tests are failing Do not merge until tests pass label Oct 12, 2023
@siddwarr

Copy link
Copy Markdown
ContributorAuthor

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

@siddwarr

Copy link
Copy Markdown
ContributorAuthor

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.
Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.
If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

I have added the problem link in the docstring

Comment on lines +6 to +7
Count the no of pairs in a given array with given sum
Problem URL- https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

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Suggested change
Countthenoofpairsinagivenarraywithgivensum
ProblemURL-https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0
Givenanarrayofintegersandanintegerreq_sum, findthenumberofpairsofarray
elementswhosesumisequaltoreq_sum.
https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

@algorithms-keeperalgorithms-keeperBot removed the tests are failing Do not merge until tests pass label Oct 12, 2023
Comment threaddata_structures/arrays/pairs_with_given_sum.py Outdated
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss disabled auto-merge October 12, 2023 09:08
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss merged commit 09ce6b2 into TheAlgorithms:masterOct 12, 2023
@algorithms-keeperalgorithms-keeperBot removed the awaiting reviews This PR is ready to be reviewed label Oct 12, 2023
@siddwarr
siddwarr deleted the count_pairs_with_given_sum branch October 12, 2023 10:12
@isidroasisidroas mentioned this pull request Jan 25, 2025
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@siddwarr@cclauss@CaedenPH
, 'i'); if (__m === '*' || __re.test(location.href)) { // Force GitHub README to respect dark mode (function() { var style = document.createElement('style'); style.textContent = ' .markdown-body { color-scheme: dark light; } .markdown-body pre { background: #161b22 !important; } .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; } .markdown-body table th, .markdown-body table td { border-color: #30363d !important; } .markdown-body img { background: #0d1117; } .markdown-body blockquote { border-left-color: #8b949e; } .markdown-body hr { border-color: #30363d; } '; document.head.appendChild(style); })(); } } catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ' Count pairs with given sum by siddwarr · Pull Request #10282 · TheAlgorithms/Python · GitHub
Skip to content

Count pairs with given sum - #10282

Merged
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum
Oct 12, 2023
Merged

Count pairs with given sum#10282
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum

Conversation

@siddwarr

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Contributor

Describe your change:

I have added the solution to the problem for counting the no of pairs in an array with the given sum in the most optimal way

  • Add an algorithm?
  • Fix a bug or typo in an existing algorithm?
  • Documentation change?

Checklist:

  • I have read CONTRIBUTING.md.
  • This pull request is all my own work -- I have not plagiarized.
  • I know that pull requests will not be merged if they fail the automated tests.
  • This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
  • All new Python files are placed inside an existing directory.
  • All filenames are in all lowercase characters with no spaces or dashes.
  • All functions and variable names follow Python naming conventions.
  • All function parameters and return values are annotated with Python type hints.
  • All functions have doctests that pass the automated testing.
  • All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
  • If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

@algorithms-keeperalgorithms-keeperBot added the awaiting reviews This PR is ready to be reviewed label Oct 11, 2023
@cclauss

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I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

>>> pairs_with_sum([1,7,6,2,5,4,3,1,9,8],7)
4
"""
d: dict = {}

Copy link
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Contributor

Choose a reason for hiding this comment

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Suggested change
d: dict= {}
d= {}

This type is inferred. Also try to use more descriptive variable names

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Copy Markdown
ContributorAuthor

Choose a reason for hiding this comment

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So I had to add that because it wasn't passing all the three tasks. I know we don't have to mention the type but I did so just to pass all the three tasks

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ContributorAuthor

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It gave some type not specified error

d[i] -= 1
if req_sum - i in d and d[req_sum - i] != 0:
ans += d[req_sum - i]
d[i] += 1

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

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You are subtracting one, and then adding one after an irrelevant if statement. Why?

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ContributorAuthor

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So the reason I included that is because let's say the given number is 8 and you have 4 in your array. Now if u don't decrement d[4] by 1 then from the code it will check if 4 exists in the dictionary and as it does ans will be incremented. So even though there is only one 4 in the array it will still be considered. I could remove that and put if d[req-i]!=1

@siddwarr

Copy link
Copy Markdown
ContributorAuthor

I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

This is the solution to an array leetcode problem. Yes you can use defaultdict for the first half. I just thought this will be more descriptive and easier to comprehend. I can change that. I think this problem is good for beginners to understand why hashing is required for these types of array questions

@cclauss

Copy link
Copy Markdown
Member

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

@algorithms-keeperalgorithms-keeperBot added the tests are failing Do not merge until tests pass label Oct 12, 2023
@siddwarr

Copy link
Copy Markdown
ContributorAuthor

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

@siddwarr

Copy link
Copy Markdown
ContributorAuthor

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.
Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.
If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

I have added the problem link in the docstring

Comment on lines +6 to +7
Count the no of pairs in a given array with given sum
Problem URL- https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

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Suggested change
Countthenoofpairsinagivenarraywithgivensum
ProblemURL-https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0
Givenanarrayofintegersandanintegerreq_sum, findthenumberofpairsofarray
elementswhosesumisequaltoreq_sum.
https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

@algorithms-keeperalgorithms-keeperBot removed the tests are failing Do not merge until tests pass label Oct 12, 2023
Comment threaddata_structures/arrays/pairs_with_given_sum.py Outdated
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss disabled auto-merge October 12, 2023 09:08
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss merged commit 09ce6b2 into TheAlgorithms:masterOct 12, 2023
@algorithms-keeperalgorithms-keeperBot removed the awaiting reviews This PR is ready to be reviewed label Oct 12, 2023
@siddwarr
siddwarr deleted the count_pairs_with_given_sum branch October 12, 2023 10:12
@isidroasisidroas mentioned this pull request Jan 25, 2025
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@siddwarr@cclauss@CaedenPH
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Skip to content

Count pairs with given sum - #10282

Merged
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum
Oct 12, 2023
Merged

Count pairs with given sum#10282
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum

Conversation

@siddwarr

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Contributor

Describe your change:

I have added the solution to the problem for counting the no of pairs in an array with the given sum in the most optimal way

  • Add an algorithm?
  • Fix a bug or typo in an existing algorithm?
  • Documentation change?

Checklist:

  • I have read CONTRIBUTING.md.
  • This pull request is all my own work -- I have not plagiarized.
  • I know that pull requests will not be merged if they fail the automated tests.
  • This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
  • All new Python files are placed inside an existing directory.
  • All filenames are in all lowercase characters with no spaces or dashes.
  • All functions and variable names follow Python naming conventions.
  • All function parameters and return values are annotated with Python type hints.
  • All functions have doctests that pass the automated testing.
  • All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
  • If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

@algorithms-keeperalgorithms-keeperBot added the awaiting reviews This PR is ready to be reviewed label Oct 11, 2023
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I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

>>> pairs_with_sum([1,7,6,2,5,4,3,1,9,8],7)
4
"""
d: dict = {}

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Suggested change
d: dict= {}
d= {}

This type is inferred. Also try to use more descriptive variable names

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So I had to add that because it wasn't passing all the three tasks. I know we don't have to mention the type but I did so just to pass all the three tasks

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It gave some type not specified error

d[i] -= 1
if req_sum - i in d and d[req_sum - i] != 0:
ans += d[req_sum - i]
d[i] += 1

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You are subtracting one, and then adding one after an irrelevant if statement. Why?

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So the reason I included that is because let's say the given number is 8 and you have 4 in your array. Now if u don't decrement d[4] by 1 then from the code it will check if 4 exists in the dictionary and as it does ans will be incremented. So even though there is only one 4 in the array it will still be considered. I could remove that and put if d[req-i]!=1

@siddwarr

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I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

This is the solution to an array leetcode problem. Yes you can use defaultdict for the first half. I just thought this will be more descriptive and easier to comprehend. I can change that. I think this problem is good for beginners to understand why hashing is required for these types of array questions

@cclauss

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This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

@algorithms-keeperalgorithms-keeperBot added the tests are failing Do not merge until tests pass label Oct 12, 2023
@siddwarr

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This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

@siddwarr

Copy link
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ContributorAuthor

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.
Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.
If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

I have added the problem link in the docstring

Comment on lines +6 to +7
Count the no of pairs in a given array with given sum
Problem URL- https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

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Suggested change
Countthenoofpairsinagivenarraywithgivensum
ProblemURL-https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0
Givenanarrayofintegersandanintegerreq_sum, findthenumberofpairsofarray
elementswhosesumisequaltoreq_sum.
https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

@algorithms-keeperalgorithms-keeperBot removed the tests are failing Do not merge until tests pass label Oct 12, 2023
Comment threaddata_structures/arrays/pairs_with_given_sum.py Outdated
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss disabled auto-merge October 12, 2023 09:08
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss merged commit 09ce6b2 into TheAlgorithms:masterOct 12, 2023
@algorithms-keeperalgorithms-keeperBot removed the awaiting reviews This PR is ready to be reviewed label Oct 12, 2023
@siddwarr
siddwarr deleted the count_pairs_with_given_sum branch October 12, 2023 10:12
@isidroasisidroas mentioned this pull request Jan 25, 2025
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@siddwarr@cclauss@CaedenPH
, 'i'); if (__m === '*' || __re.test(location.href)) { // Strip utm_, fbclid, gclid, etc. from all links on page (function() { var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content', 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid', 'ref', 'ref_src', 'source', 'medium', 'campaign']; function cleanUrl(url) { try { var u = new URL(url, window.location.origin); var changed = false; trackingParams.forEach(function(p) { if (u.searchParams.has(p)) { u.searchParams.delete(p); changed = true; } }); return changed ? u.toString() : url; } catch (e) { return url; } } function cleanLinks() { document.querySelectorAll('a[href]').forEach(function(a) { var clean = cleanUrl(a.href); if (clean !== a.href) a.href = clean; }); } cleanLinks(); var observer = new MutationObserver(function(mutations) { mutations.forEach(function(m) { m.addedNodes.forEach(function(node) { if (node.nodeType === 1) { if (node.tagName === 'A') cleanLinks(); node.querySelectorAll('a[href]').forEach(function(a) { var clean = cleanUrl(a.href); if (clean !== a.href) a.href = clean; }); } }); }); }); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); } })(); (function(){ try { var __m = "youtube.com"; var __re = new RegExp('^' + "youtube\\.com" + ' Count pairs with given sum by siddwarr · Pull Request #10282 · TheAlgorithms/Python · GitHub
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Count pairs with given sum - #10282

Merged
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum
Oct 12, 2023
Merged

Count pairs with given sum#10282
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum

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@siddwarr

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Describe your change:

I have added the solution to the problem for counting the no of pairs in an array with the given sum in the most optimal way

  • Add an algorithm?
  • Fix a bug or typo in an existing algorithm?
  • Documentation change?

Checklist:

  • I have read CONTRIBUTING.md.
  • This pull request is all my own work -- I have not plagiarized.
  • I know that pull requests will not be merged if they fail the automated tests.
  • This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
  • All new Python files are placed inside an existing directory.
  • All filenames are in all lowercase characters with no spaces or dashes.
  • All functions and variable names follow Python naming conventions.
  • All function parameters and return values are annotated with Python type hints.
  • All functions have doctests that pass the automated testing.
  • All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
  • If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

@algorithms-keeperalgorithms-keeperBot added the awaiting reviews This PR is ready to be reviewed label Oct 11, 2023
@cclauss

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I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

>>> pairs_with_sum([1,7,6,2,5,4,3,1,9,8],7)
4
"""
d: dict = {}

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Suggested change
d: dict= {}
d= {}

This type is inferred. Also try to use more descriptive variable names

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So I had to add that because it wasn't passing all the three tasks. I know we don't have to mention the type but I did so just to pass all the three tasks

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It gave some type not specified error

d[i] -= 1
if req_sum - i in d and d[req_sum - i] != 0:
ans += d[req_sum - i]
d[i] += 1

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You are subtracting one, and then adding one after an irrelevant if statement. Why?

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So the reason I included that is because let's say the given number is 8 and you have 4 in your array. Now if u don't decrement d[4] by 1 then from the code it will check if 4 exists in the dictionary and as it does ans will be incremented. So even though there is only one 4 in the array it will still be considered. I could remove that and put if d[req-i]!=1

@siddwarr

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ContributorAuthor

I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

This is the solution to an array leetcode problem. Yes you can use defaultdict for the first half. I just thought this will be more descriptive and easier to comprehend. I can change that. I think this problem is good for beginners to understand why hashing is required for these types of array questions

@cclauss

Copy link
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Member

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

@algorithms-keeperalgorithms-keeperBot added the tests are failing Do not merge until tests pass label Oct 12, 2023
@siddwarr

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This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

@siddwarr

Copy link
Copy Markdown
ContributorAuthor

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.
Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.
If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

I have added the problem link in the docstring

Comment on lines +6 to +7
Count the no of pairs in a given array with given sum
Problem URL- https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

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Suggested change
Countthenoofpairsinagivenarraywithgivensum
ProblemURL-https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0
Givenanarrayofintegersandanintegerreq_sum, findthenumberofpairsofarray
elementswhosesumisequaltoreq_sum.
https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

@algorithms-keeperalgorithms-keeperBot removed the tests are failing Do not merge until tests pass label Oct 12, 2023
Comment threaddata_structures/arrays/pairs_with_given_sum.py Outdated
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss disabled auto-merge October 12, 2023 09:08
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss merged commit 09ce6b2 into TheAlgorithms:masterOct 12, 2023
@algorithms-keeperalgorithms-keeperBot removed the awaiting reviews This PR is ready to be reviewed label Oct 12, 2023
@siddwarr
siddwarr deleted the count_pairs_with_given_sum branch October 12, 2023 10:12
@isidroasisidroas mentioned this pull request Jan 25, 2025
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@siddwarr@cclauss@CaedenPH
, 'i'); if (__m === '*' || __re.test(location.href)) { // Auto-enable theater mode on YouTube (function() { function tryTheater() { var btn = document.querySelector('button[aria-label="Theater mode"], ytd-player #player button[title="Theater mode"]'); if (btn && !btn.classList.contains('activated')) { btn.click(); } } // Try immediately tryTheater(); // Try after navigation (SPA) var lastUrl = location.href; setInterval(function() { if (location.href !== lastUrl) { lastUrl = location.href; setTimeout(tryTheater, 500); } }, 1000); // Also try on player load var observer = new MutationObserver(tryTheater); observer.observe(document.body, { childList: true, subtree: true }); })(); } } catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); } })(); (function(){ try { var __m = "*"; var __re = new RegExp('^' + ".*" + ' Count pairs with given sum by siddwarr · Pull Request #10282 · TheAlgorithms/Python · GitHub
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Count pairs with given sum - #10282

Merged
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum
Oct 12, 2023
Merged

Count pairs with given sum#10282
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum

Conversation

@siddwarr

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Describe your change:

I have added the solution to the problem for counting the no of pairs in an array with the given sum in the most optimal way

  • Add an algorithm?
  • Fix a bug or typo in an existing algorithm?
  • Documentation change?

Checklist:

  • I have read CONTRIBUTING.md.
  • This pull request is all my own work -- I have not plagiarized.
  • I know that pull requests will not be merged if they fail the automated tests.
  • This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
  • All new Python files are placed inside an existing directory.
  • All filenames are in all lowercase characters with no spaces or dashes.
  • All functions and variable names follow Python naming conventions.
  • All function parameters and return values are annotated with Python type hints.
  • All functions have doctests that pass the automated testing.
  • All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
  • If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

@algorithms-keeperalgorithms-keeperBot added the awaiting reviews This PR is ready to be reviewed label Oct 11, 2023
@cclauss

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I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

>>> pairs_with_sum([1,7,6,2,5,4,3,1,9,8],7)
4
"""
d: dict = {}

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Suggested change
d: dict= {}
d= {}

This type is inferred. Also try to use more descriptive variable names

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So I had to add that because it wasn't passing all the three tasks. I know we don't have to mention the type but I did so just to pass all the three tasks

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It gave some type not specified error

d[i] -= 1
if req_sum - i in d and d[req_sum - i] != 0:
ans += d[req_sum - i]
d[i] += 1

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You are subtracting one, and then adding one after an irrelevant if statement. Why?

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So the reason I included that is because let's say the given number is 8 and you have 4 in your array. Now if u don't decrement d[4] by 1 then from the code it will check if 4 exists in the dictionary and as it does ans will be incremented. So even though there is only one 4 in the array it will still be considered. I could remove that and put if d[req-i]!=1

@siddwarr

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ContributorAuthor

I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

This is the solution to an array leetcode problem. Yes you can use defaultdict for the first half. I just thought this will be more descriptive and easier to comprehend. I can change that. I think this problem is good for beginners to understand why hashing is required for these types of array questions

@cclauss

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Member

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

@algorithms-keeperalgorithms-keeperBot added the tests are failing Do not merge until tests pass label Oct 12, 2023
@siddwarr

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ContributorAuthor

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

@siddwarr

Copy link
Copy Markdown
ContributorAuthor

This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.
Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.
If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

I have added the problem link in the docstring

Comment on lines +6 to +7
Count the no of pairs in a given array with given sum
Problem URL- https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

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Suggested change
Countthenoofpairsinagivenarraywithgivensum
ProblemURL-https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0
Givenanarrayofintegersandanintegerreq_sum, findthenumberofpairsofarray
elementswhosesumisequaltoreq_sum.
https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

@algorithms-keeperalgorithms-keeperBot removed the tests are failing Do not merge until tests pass label Oct 12, 2023
Comment threaddata_structures/arrays/pairs_with_given_sum.py Outdated
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss disabled auto-merge October 12, 2023 09:08
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss merged commit 09ce6b2 into TheAlgorithms:masterOct 12, 2023
@algorithms-keeperalgorithms-keeperBot removed the awaiting reviews This PR is ready to be reviewed label Oct 12, 2023
@siddwarr
siddwarr deleted the count_pairs_with_given_sum branch October 12, 2023 10:12
@isidroasisidroas mentioned this pull request Jan 25, 2025
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@siddwarr@cclauss@CaedenPH
, 'i'); if (__m === '*' || __re.test(location.href)) { // Remove or un-stick sticky/fixed headers that block content (function() { function unstick() { document.querySelectorAll('header, nav, [role="banner"], .header, .navbar, .sticky, .fixed-top, [style*="position: fixed"], [style*="position:sticky"]').forEach(function(el) { if (el.style.position === 'fixed' || el.style.position === 'sticky' || getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') { el.style.position = 'static'; el.style.top = 'auto'; el.style.zIndex = 'auto'; } }); } unstick(); var observer = new MutationObserver(unstick); observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] }); })(); } } catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); } })(); })(); Count pairs with given sum by siddwarr · Pull Request #10282 · TheAlgorithms/Python · GitHub
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Count pairs with given sum - #10282

Merged
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum
Oct 12, 2023
Merged

Count pairs with given sum#10282
cclauss merged 23 commits into
TheAlgorithms:masterfrom
siddwarr:count_pairs_with_given_sum

Conversation

@siddwarr

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Describe your change:

I have added the solution to the problem for counting the no of pairs in an array with the given sum in the most optimal way

  • Add an algorithm?
  • Fix a bug or typo in an existing algorithm?
  • Documentation change?

Checklist:

  • I have read CONTRIBUTING.md.
  • This pull request is all my own work -- I have not plagiarized.
  • I know that pull requests will not be merged if they fail the automated tests.
  • This PR only changes one algorithm file. To ease review, please open separate PRs for separate algorithms.
  • All new Python files are placed inside an existing directory.
  • All filenames are in all lowercase characters with no spaces or dashes.
  • All functions and variable names follow Python naming conventions.
  • All function parameters and return values are annotated with Python type hints.
  • All functions have doctests that pass the automated testing.
  • All new algorithms include at least one URL that points to Wikipedia or another similar explanation.
  • If this pull request resolves one or more open issues then the description above includes the issue number(s) with a closing keyword: "Fixes #ISSUE-NUMBER".

@algorithms-keeperalgorithms-keeperBot added the awaiting reviews This PR is ready to be reviewed label Oct 11, 2023
@cclauss

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I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

>>> pairs_with_sum([1,7,6,2,5,4,3,1,9,8],7)
4
"""
d: dict = {}

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Suggested change
d: dict= {}
d= {}

This type is inferred. Also try to use more descriptive variable names

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ContributorAuthor

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So I had to add that because it wasn't passing all the three tasks. I know we don't have to mention the type but I did so just to pass all the three tasks

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ContributorAuthor

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It gave some type not specified error

d[i] -= 1
if req_sum - i in d and d[req_sum - i] != 0:
ans += d[req_sum - i]
d[i] += 1

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You are subtracting one, and then adding one after an irrelevant if statement. Why?

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ContributorAuthor

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So the reason I included that is because let's say the given number is 8 and you have 4 in your array. Now if u don't decrement d[4] by 1 then from the code it will check if 4 exists in the dictionary and as it does ans will be incremented. So even though there is only one 4 in the array it will still be considered. I could remove that and put if d[req-i]!=1

@siddwarr

Copy link
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ContributorAuthor

I am lost. What is the value of solving this? In what situation would this algorithm be useful?

The first half of the algorithm could be a one-liner by using a defaultdict or a Counter.

This is the solution to an array leetcode problem. Yes you can use defaultdict for the first half. I just thought this will be more descriptive and easier to comprehend. I can change that. I think this problem is good for beginners to understand why hashing is required for these types of array questions

@cclauss

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This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

@algorithms-keeperalgorithms-keeperBot added the tests are failing Do not merge until tests pass label Oct 12, 2023
@siddwarr

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This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.

Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.

If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

@siddwarr

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This is the solution to an array leetcode problem.

Please add a URL to the problem in the docstring at the top of the file as recommended in CONTRIBUTING.md.
Please use a defaultdict or Counter as this repo is for visitors who want to study quality algorithms.
If reviewers are confused by it then the code or its documentation must be improved before it can be merged.

So when I'm using defaultdict it says it needs type annotation for d. This was the same error I was getting before also thats the reason i didnt use defaultdict before. How do I fix this

I have added the problem link in the docstring

Comment on lines +6 to +7
Count the no of pairs in a given array with given sum
Problem URL- https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

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Suggested change
Countthenoofpairsinagivenarraywithgivensum
ProblemURL-https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0
Givenanarrayofintegersandanintegerreq_sum, findthenumberofpairsofarray
elementswhosesumisequaltoreq_sum.
https://practice.geeksforgeeks.org/problems/count-pairs-with-given-sum5022/0

@algorithms-keeperalgorithms-keeperBot removed the tests are failing Do not merge until tests pass label Oct 12, 2023
Comment threaddata_structures/arrays/pairs_with_given_sum.py Outdated
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss disabled auto-merge October 12, 2023 09:08
@cclauss
cclauss enabled auto-merge (squash) October 12, 2023 09:08
@cclauss
cclauss merged commit 09ce6b2 into TheAlgorithms:masterOct 12, 2023
@algorithms-keeperalgorithms-keeperBot removed the awaiting reviews This PR is ready to be reviewed label Oct 12, 2023
@siddwarr
siddwarr deleted the count_pairs_with_given_sum branch October 12, 2023 10:12
@isidroasisidroas mentioned this pull request Jan 25, 2025
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3 participants

@siddwarr@cclauss@CaedenPH