| 1 | Two Sum | Use a hash table to keep track of the indices of the numbers you've encountered so far. | JS Solution | Python Solution |
| 3 | Longest Substring Without Repeating Chars | What if index of the first occurrence might help? | JS Solution | Python Solution |
| 7 | Reverse Integer | | JS Solution | Python Solution |
| 9 | Palindrome Number | Use two pointers to make it work faster. Beware of overflow. | JS Solution | Python Solution |
| 20 | Valid Parentheses | Use a stack of characters. When you encounter a closing bracket, check if the top of the stack was the opening for it. If yes, pop it from the stack. Otherwise, return false. | JS Solution | Python Solution |
| 28 | Find the Index of the First Occurrence in a String | | JS Solution | Python Solution |
| 32 | Longest Valid Parentheses | Use a stack of characters. | JS Solution | Python Solution |
| 34 | Find First and Last Position of Element in Sorted Array | Binary Search | JS Solution | Python Solution |
| 35 | Search Insert Position | Use binary search | JS Solution | Python Solution |
| 42 | Trapping Rain Water | | JS Solution | Python Solution |
| 58 | Length of Last Word | Filter out the words and empty strings in the words array. Don't forget about removing spaces. | JS Solution | Python Solution |
| 62 | Unique Paths | Dynamic programming is one of the effective ways to solve it. Just find recurrent formula. | JS Solution | Python Solution |
| 63 | Unique Paths II | Use dynamic programming since, from each cell, you can move to the right or down. | JS Solution | Python Solution |
| 64 | Minimum Path Sum | Remember that from the second cell, the value of the current cell is the price of the current cell plus the minimum value of the previous ones | JS Solution | Python Solution |
| 66 | Plus One | Try iterating through each digit backwards. What do you do when the digit is a 9? | JS Solution | Python Solution |
| 69 | Sqrt | Use binary search to make algorithm work faster | JS Solution | Python Solution |
| 70 | Climbing Stairs | To reach nth step, what could have been your previous steps? | JS Solution | Python Solution |
| 75 | Sort Colors | Overwrite array with the total number of 0's, then 1's and followed by 2's. Any sort might be appropriate solution. | JS Solution | Python Solution |
| 88 | Merge Sorted Array | You can easily solve this problem if you simply think about two elements at a time rather than two arrays. We know that each of the individual arrays is sorted. What we don't know is how they will intertwine. Can we take a local decision and arrive at an optimal solution? | JS Solution | Python Solution |
| 122 | Best Time to Buy and Sell Stock II | What should we do every time there is a valley followed by a peak in price? | JS Solution | Python Solution |
| 125 | Valid Palindrome | Use Two Pointers | JS Solutions | Python Solution |
| 136 | Single Number | Use Bit Manipulations (XOR) | JS Solution | Python Solution |
| 151 | Reverse Words in a String | | JS Solution | Python Solution |
| 155 | Min Stack | | JS Solution | Python Solution |
| 169 | Majority Element | | JS Solution | Python Solution |
| 191 | Number of 1 Bits | Use Bit Manipulations | JS Solution | Python Solution |
| 197 | Rising Temperature | | SQL Solution | Pandas Solution |
| 202 | Happy Number | | JS Solution | Python Solution |
| 204 | Count Primes | Use Sieve of Eratosthenes. | JS Solution | Python Solution |
| 206 | Reverse Linked List | | JS Solution | Python Solution |
| 217 | Contains Duplicate | | JS Solution | Python Solution |
| 231 | Power Of Two | Think of Bit Manipulations | JS Solution | Python Solution |
| 232 | Implement Queue using Stacks | | JS Solution | Python Solution |
| 242 | Valid Anagram | | JS Solution | Python Solution |
| 263 | Ugly Number | | JS Solution | Python Solution |
| 264 | Ugly Number II | Dynamic Programming | JS Solution | Python Solution |
| 268 | Missing Number | Bit Manipulation is One of the Options | JS Solution | Python Solution |
| 300 | Longest Increasing Subsequence | Compare two last nums in sequence and subsequence. If both are equal, length of LIS is increased by 1 | JS Solution | Python Solution |
| 322 | Coin Change | Think how to use a knapsack problem | JS Solution | Python Solution |
| 326 | Power of Three | | JS Solution | Python Solution |
| 342 | Power of Four | Bit Manipulations | JS Solutions | Python Solution |
| 344 | Reverse String | The entire logic for reversing a string is based on using the opposite directional two-pointer approach | JS Solution | Python Solution |
| 345 | Reverse Vowels of a String | | JS Solution | Python Solution |
| 367 | Valid Perfect Square | | JS Solution | Python Solution |
| 389 | Find The Difference | | JS Solution | Python Solution |
| 392 | Is Subsequence | Use two pointers to iterate through the two strings simultaneously. | JS Solution | Python Solution |
| 412 | Fizz Buzz | The first non-standard value must satisfy both conditions. | JS Solution | Python Solution |
| 421 | Maximum XOR of Two Numbers in an Array | | JS Solution | Python Solution |
| 451 | Sort Characters By Frequency | | JS Solution | Python Solution |
| 461 | Hamming Distance | Bit Manipulation (XOR) | JS Solution | Python Solution |
| 504 | Base 7 | Gorner's algorithm can help with this problem | JS Solution | Python Solution |
| 516 | Longest Palindromic Subsequence | | JS Solution | Python Solution |
| 557 | Reverse Words in a String III | | JS Solution | Python Solution |
| 550 | Game Analysis IV | | SQL Solution | Pandas Solution |
| 577 | Employee Bonus | | SQL Solution | Pandas Solution |
| 580 | Managers With At Least 5 Direct Reports | | SQL Solution | Pandas Solution |
| 584 | Find Customer Referee | | SQL Solution | Pandas Solution |
| 595 | Big Countries | | SQL Solution | Pandas Solution |
| 596 | Classes More Than 5 Students | | SQL Solution | Pandas Solution |
| 610 | Triangle Judgement | | SQL Solution | Pandas Solution |
| 619 | Biggest Single Number | | SQL Solution | Pandas Solution |
| 620 | Not Boring Movies | | SQL Solution | Pandas Solution |
| 704 | Binary Search | | JS Solution | Python Solution |
| 771 | Jewels and Stones | | JS Solution | Python Solution |
| 1045 | Customers Who Bought All Products | | SQL Solution | Pandas Solution |
| 1068 | Products Sales Analysis I | | SQL Solution | Pandas Solution |
| 1070 | Products Sales Analysis III | | SQL Solution | Pandas Solution |
| 1075 | Project Employees I | | SQL Solution | Pandas Solution |
| 1137 | N-th Tribonacci Number | Use dynamic programming | JS Solution | Python Solution |
| 1141 | User Activity for the Past 30 Days I | | SQL Solution | Pandas Solution |
| 1143 | Longest Common Subsequence | Try dynamic programming. DP[i][j] represents the longest common subsequence of text1[0 ... i] & text2[0 ... j]. | JS Solution | Python Solution |
| 1148 | Article Views I | | SQL Solution | Pandas Solution |
| 1174 | Immediate Food Delivery II | | SQL Solution | Pandas Solution |
| 1193 | Monthly Transactions I | | SQL Solution | Pandas Solution |
| 1207 | Unique Number of Occurrences | Find the number of occurrences of each element in the array using a hash map. | JS Solution | Python Solution |
| 1211 | Queries Quality And Percentage | | SQL Solution | Pandas Solution |
| 1251 | Average Selling Price | | SQL Solution | Pandas Solution |
| 1280 | Students And Examinations | | SQL Solution | Pandas Solution |
| 1287 | Element Appearing More Than 25% In Sorted Array | | JS Solution | Python Solution |
| 1378 | Replace Employee ID With The Unique Identifier | | SQL Solution | Pandas Solution |
| 1381 | Design a Stack With Increment Operation | | JS Solution | Python Solution |
| 1523 | Count Odd Numbers in an Interval Range | | JS Solution | Python Solution |
| 1581 | Customer Who Visited But Did Not Make Any Transactions | | SQL Solution | Pandas Solution |
| 1633 | Percentage Of Users Attended A Contest | | SQL Solution | Pandas Solution |
| 1661 | Average Time Of Process Per Machine | | SQL Solution | Pandas Solution |
| 1683 | Invalid Tweets | | SQL Solution | Pandas Solution |
| 1729 | Find Followers Count | | SQL Solution | Pandas Solution |
| 1731 | The Number Of Employee Which Report To Each Employee | | SQL Solution | Pandas Solution |
| 1757 | Recycle And Low Fat Products | | SQL Solution | Pandas Solution |
| 1934 | Confirmation Rate | | SQL Solution | Pandas Solution |
| 1934 | Confirmation Rate | | SQL Solution | Pandas Solution |
| 2356 | Number of Unique Subjects Taught by Each Teacher | | SQL Solution | Pandas Solution |
| 2455 | Average Value of Even Numbers That Are Divisible by Three | | JS Solution | Python Solution |