EPI Judge

Introduction

EPI Judge consists of the following:

• Stub programs for each problem in our book in Python, Java, and C++
• Test-cases that cover common corner-case and performance bugs
• A framework for running these tests on your implementation on your machine

Installation

Here's how to download the judge:

$ git clone https://github.com/adnanaziz/EPIJudge.git

If you do not have git, here's a good tutorial on installing git itself.

Running the judge using IDEs

Check out these one minute videos to see how easy it is to get started with the judge.

Python

PyCharm, Eclipse, NetBeans

Java

IntelliJ IDEA, Eclipse

C++

CLion, Visual Studio 2017

Running the judge from the command line

Python

$ python3 <program_name>.py

Java

Use the Makefile.

Compile and run a specific program:

$ make <program_name> 

Example:

$ make Anagrams

Compile and run the last program that you edited:

$ make

C++

You can manually compile and run all programs by directly invoking GCC and Clang.

$ g++ -pthread -std=c++14 -O3 -o anagrams anagrams.cc

You can also use the provided Makefile: make <program_name>. You can also use CMake with the provided CMakeLists.txt file.

$ make 

The default Makefile target is the last edited file.

$ make anagrams

FAQ

• How can I contact the authors?

Please feel free to send us questions and feedback - adnan.aziz@gmail.com and tsung.hsien.lee@gmail.com

• Help, my EPIJudge is not working, what should I do?

If you do have issues, e.g., with install or with buggy tests, feel free to reach out to us via email. Please be as detailed as you can: the ideal is if you can upload a screencast video of the issue to youtube; failing that, please upload screenshots. The more detailed the description of the problem and your environment (OS, language version, IDE and version), the easier it’ll be for us to help you.

• I'm new to programming, and don't have any kind of development environment, what should I do?

The IntelliJ Integrated Development environments described above are best-in-class, and have free versions that will work fine for the EPI Judge. They do not include the compilers. You can get the Java development environment from Oracle, and the Python development environment from Python.org. For C++, you have multiple options. The simplest is to install VisualStudio, which includes both the IDE and the compiler. Google is a good resource for installation help.

• What compilers are supported for judge?

  • C++
    • Linux
      • GCC 5.4.1
      • Clang 4.0
    • OS X
      • Apple LLVM Clang 9.0.0
    • Windows
      • Visual Studio 2017 15.7.0 Preview 6
        • Release version of VS2017 contains a bug that makes it impossible to compile judge programs
      • MinGW GCC 5.4.0
      • LXSS (Windows Subsystem for Linux) GCC 5.4.0
  • Java
    • Java 9
  • Python
    • Python 3.6

• What compilers are supported for solutions?

  • C++
    • Linux
      • GCC 7.0.0
      • Clang 5.0
    • OS X
      • Apple LLVM Clang 9.0.0
    • Windows
      • Visual Studio 2017 15.7.0 Preview 6
        • Release version of VS2017 contains a bug that makes it impossible to compile judge programs
      • MinGW GCC 7.2.0
      • LXSS (Windows Subsystem for Linux) GCC 7.2.0
    • Java
      • Java 9
    • Python
      • Python 3.6

Let us know if you managed to compile with an older version.

• What does the UI look like?

Take a look at this screenshot.

• How can I understand the test framework better?

The judge harness is fairly complex (but does not use nonstandard language features or libraries). You are welcome to study it, but we’d advise you against making changes to it (since it will lead to nasty merge conflicts when you update).

• How do I import the C++ project?

If you want to import the project into your favourite IDE, you probably need to create IDE project with CMake (no need to do it for CLion, it supports CMake out-of-the-box).

Here is an example recipe for generationg Visual Studio project (list of all CMake supported IDEs). After installing CMake, open your terminal, go to epi_judge_cpp folder and run following commands:

mkdir vs
cd vs
cmake -G "Visual Studio 15 2017" ..

Then just open epi_judge_cpp/vs/epi_judge_cpp.sln solution with Visual Studio and it will load all EPI programs.

Problem to Program Mapping

(You may have to scroll to the right to view the Python column.)

Problem	C++	Java	Python
Bootcamp: Primitive Types	count_bits.cc	CountBits.java	count_bits.py
Computing the parity of a word	parity.cc	Parity.java	parity.py
Swap bits	swap_bits.cc	SwapBits.java	swap_bits.py
Reverse bits	reverse_bits.cc	ReverseBits.java	reverse_bits.py
Find a closest integer with the same weight	closest_int_same_weight.cc	ClosestIntSameWeight.java	closest_int_same_weight.py
Compute x * y without arithmetical operators	primitive_multiply.cc	PrimitiveMultiply.java	primitive_multiply.py
Compute x/y	primitive_divide.cc	PrimitiveDivide.java	primitive_divide.py
Compute x^y	power_x_y.cc	PowerXY.java	power_x_y.py
Reverse digits	reverse_digits.cc	ReverseDigits.java	reverse_digits.py
Check if a decimal integer is a palindrome	is_number_palindromic.cc	IsNumberPalindromic.java	is_number_palindromic.py
Generate uniform random numbers	uniform_random_number.cc	UniformRandomNumber.java	uniform_random_number.py
Rectangle intersection	rectangle_intersection.cc	RectangleIntersection.java	rectangle_intersection.py
Bootcamp: Arrays	even_odd_array.cc	EvenOddArray.java	even_odd_array.py
The Dutch national flag problem	dutch_national_flag.cc	DutchNationalFlag.java	dutch_national_flag.py
Increment an arbitrary-precision integer	int_as_array_increment.cc	IntAsArrayIncrement.java	int_as_array_increment.py
Multiply two arbitrary-precision integers	int_as_array_multiply.cc	IntAsArrayMultiply.java	int_as_array_multiply.py
Advancing through an array	advance_by_offsets.cc	AdvanceByOffsets.java	advance_by_offsets.py
Delete duplicates from a sorted array	sorted_array_remove_dups.cc	SortedArrayRemoveDups.java	sorted_array_remove_dups.py
Buy and sell a stock once	buy_and_sell_stock.cc	BuyAndSellStock.java	buy_and_sell_stock.py
Buy and sell a stock twice	buy_and_sell_stock_twice.cc	BuyAndSellStockTwice.java	buy_and_sell_stock_twice.py
Computing an alternation	alternating_array.cc	AlternatingArray.java	alternating_array.py
Enumerate all primes to n	prime_sieve.cc	PrimeSieve.java	prime_sieve.py
Permute the elements of an array	apply_permutation.cc	ApplyPermutation.java	apply_permutation.py
Compute the next permutation	next_permutation.cc	NextPermutation.java	next_permutation.py
Sample offline data	offline_sampling.cc	OfflineSampling.java	offline_sampling.py
Sample online data	online_sampling.cc	OnlineSampling.java	online_sampling.py
Compute a random permutation	random_permutation.cc	RandomPermutation.java	random_permutation.py
Compute a random subset	random_subset.cc	RandomSubset.java	random_subset.py
Generate nonuniform random numbers	nonuniform_random_number.cc	NonuniformRandomNumber.java	nonuniform_random_number.py
The Sudoku checker problem	is_valid_sudoku.cc	IsValidSudoku.java	is_valid_sudoku.py
Compute the spiral ordering of a 2D array	spiral_ordering_segments.cc	SpiralOrderingSegments.java	spiral_ordering_segments.py
Rotate a 2D array	matrix_rotation.cc	MatrixRotation.java	matrix_rotation.py
Compute rows in Pascal's Triangle	pascal_triangle.cc	PascalTriangle.java	pascal_triangle.py
Interconvert strings and integers	string_integer_interconversion.cc	StringIntegerInterconversion.java	string_integer_interconversion.py
Base conversion	convert_base.cc	ConvertBase.java	convert_base.py
Compute the spreadsheet column encoding	spreadsheet_encoding.cc	SpreadsheetEncoding.java	spreadsheet_encoding.py
Replace and remove	replace_and_remove.cc	ReplaceAndRemove.java	replace_and_remove.py
Test palindromicity	is_string_palindromic_punctuation.cc	IsStringPalindromicPunctuation.java	is_string_palindromic_punctuation.py
Reverse all the words in a sentence	reverse_words.cc	ReverseWords.java	reverse_words.py
Compute all mnemonics for a phone number	phone_number_mnemonic.cc	PhoneNumberMnemonic.java	phone_number_mnemonic.py
The look-and-say problem	look_and_say.cc	LookAndSay.java	look_and_say.py
Convert from Roman to decimal	roman_to_integer.cc	RomanToInteger.java	roman_to_integer.py
Compute all valid IP addresses	valid_ip_addresses.cc	ValidIpAddresses.java	valid_ip_addresses.py
Write a string sinusoidally	snake_string.cc	SnakeString.java	snake_string.py
Implement run-length encoding	run_length_compression.cc	RunLengthCompression.java	run_length_compression.py
Find the first occurrence of a substring	substring_match.cc	SubstringMatch.java	substring_match.py
Bootcamp: Linked Lists	search_in_list.cc	SearchInList.java	search_in_list.py
Bootcamp: Linked Lists	insert_in_list.cc	InsertInList.java	insert_in_list.py
Bootcamp: Linked Lists	delete_from_list.cc	DeleteFromList.java	delete_from_list.py
Merge two sorted lists	sorted_lists_merge.cc	SortedListsMerge.java	sorted_lists_merge.py
Reverse a single sublist	reverse_sublist.cc	ReverseSublist.java	reverse_sublist.py
Test for cyclicity	is_list_cyclic.cc	IsListCyclic.java	is_list_cyclic.py
Test for overlapping lists - lists are cycle-free	do_terminated_lists_overlap.cc	DoTerminatedListsOverlap.java	do_terminated_lists_overlap.py
Test for overlapping lists - lists may have cycles	do_lists_overlap.cc	DoListsOverlap.java	do_lists_overlap.py
Delete a node from a singly linked list	delete_node_from_list.cc	DeleteNodeFromList.java	delete_node_from_list.py
Remove the kth last element from a list	delete_kth_last_from_list.cc	DeleteKthLastFromList.java	delete_kth_last_from_list.py
Remove duplicates from a sorted list	remove_duplicates_from_sorted_list.cc	RemoveDuplicatesFromSortedList.java	remove_duplicates_from_sorted_list.py
Implement cyclic right shift for singly linked lists	list_cyclic_right_shift.cc	ListCyclicRightShift.java	list_cyclic_right_shift.py
Implement even-odd merge	even_odd_list_merge.cc	EvenOddListMerge.java	even_odd_list_merge.py
Test whether a singly linked list is palindromic	is_list_palindromic.cc	IsListPalindromic.java	is_list_palindromic.py
Implement list pivoting	pivot_list.cc	PivotList.java	pivot_list.py
Add list-based integers	int_as_list_add.cc	IntAsListAdd.java	int_as_list_add.py
Implement a stack with max API	stack_with_max.cc	StackWithMax.java	stack_with_max.py
Evaluate RPN expressions	evaluate_rpn.cc	EvaluateRpn.java	evaluate_rpn.py
Test a string over ''{,},(,),[,]'' for well-formedness	is_valid_parenthesization.cc	IsValidParenthesization.java	is_valid_parenthesization.py
Normalize pathnames	directory_path_normalization.cc	DirectoryPathNormalization.java	directory_path_normalization.py
Compute buildings with a sunset view	sunset_view.cc	SunsetView.java	sunset_view.py
Compute binary tree nodes in order of increasing depth	tree_level_order.cc	TreeLevelOrder.java	tree_level_order.py
Implement a circular queue	circular_queue.cc	CircularQueue.java	circular_queue.py
Implement a queue using stacks	queue_from_stacks.cc	QueueFromStacks.java	queue_from_stacks.py
Implement a queue with max API	queue_with_max.cc	QueueWithMax.java	queue_with_max.py
Test if a binary tree is height-balanced	is_tree_balanced.cc	IsTreeBalanced.java	is_tree_balanced.py
Test if a binary tree is symmetric	is_tree_symmetric.cc	IsTreeSymmetric.java	is_tree_symmetric.py
Compute the lowest common ancestor in a binary tree	lowest_common_ancestor.cc	LowestCommonAncestor.java	lowest_common_ancestor.py
Compute the LCA when nodes have parent pointers	lowest_common_ancestor_with_parent.cc	LowestCommonAncestorWithParent.java	lowest_common_ancestor_with_parent.py
Sum the root-to-leaf paths in a binary tree	sum_root_to_leaf.cc	SumRootToLeaf.java	sum_root_to_leaf.py
Find a root to leaf path with specified sum	path_sum.cc	PathSum.java	path_sum.py
Implement an inorder traversal without recursion	tree_inorder.cc	TreeInorder.java	tree_inorder.py
Implement a preorder traversal without recursion	tree_preorder.cc	TreePreorder.java	tree_preorder.py
Compute the kth node in an inorder traversal	kth_node_in_tree.cc	KthNodeInTree.java	kth_node_in_tree.py
Compute the successor	successor_in_tree.cc	SuccessorInTree.java	successor_in_tree.py
Implement an inorder traversal with O(1) space	tree_with_parent_inorder.cc	TreeWithParentInorder.java	tree_with_parent_inorder.py
Reconstruct a binary tree from traversal data	tree_from_preorder_inorder.cc	TreeFromPreorderInorder.java	tree_from_preorder_inorder.py
Reconstruct a binary tree from a preorder traversal with markers	tree_from_preorder_with_null.cc	TreeFromPreorderWithNull.java	tree_from_preorder_with_null.py
Form a linked list from the leaves of a binary tree	tree_connect_leaves.cc	TreeConnectLeaves.java	tree_connect_leaves.py
Compute the exterior of a binary tree	tree_exterior.cc	TreeExterior.java	tree_exterior.py
Compute the right sibling tree	tree_right_sibling.cc	TreeRightSibling.java	tree_right_sibling.py
Merge sorted files	sorted_arrays_merge.cc	SortedArraysMerge.java	sorted_arrays_merge.py
Sort an increasing-decreasing array	sort_increasing_decreasing_array.cc	SortIncreasingDecreasingArray.java	sort_increasing_decreasing_array.py
Sort an almost-sorted array	sort_almost_sorted_array.cc	SortAlmostSortedArray.java	sort_almost_sorted_array.py
Compute the k closest stars	k_closest_stars.cc	KClosestStars.java	k_closest_stars.py
Compute the median of online data	online_median.cc	OnlineMedian.java	online_median.py
Compute the k largest elements in a max-heap	k_largest_in_heap.cc	KLargestInHeap.java	k_largest_in_heap.py
Search a sorted array for first occurrence of k	search_first_key.cc	SearchFirstKey.java	search_first_key.py
Search a sorted array for entry equal to its index	search_entry_equal_to_index.cc	SearchEntryEqualToIndex.java	search_entry_equal_to_index.py
Search a cyclically sorted array	search_shifted_sorted_array.cc	SearchShiftedSortedArray.java	search_shifted_sorted_array.py
Compute the integer square root	int_square_root.cc	IntSquareRoot.java	int_square_root.py
Compute the real square root	real_square_root.cc	RealSquareRoot.java	real_square_root.py
Search in a 2D sorted array	search_row_col_sorted_matrix.cc	SearchRowColSortedMatrix.java	search_row_col_sorted_matrix.py
Find the min and max simultaneously	search_for_min_max_in_array.cc	SearchForMinMaxInArray.java	search_for_min_max_in_array.py
Find the kth largest element	kth_largest_in_array.cc	KthLargestInArray.java	kth_largest_in_array.py
Find the missing IP address	absent_value_array.cc	AbsentValueArray.java	absent_value_array.py
Find the duplicate and missing elements	search_for_missing_element.cc	SearchForMissingElement.java	search_for_missing_element.py
Bootcamp: Hash Tables	anagrams.cc	Anagrams.java	anagrams.py
Test for palindromic permutations	is_string_permutable_to_palindrome.cc	IsStringPermutableToPalindrome.java	is_string_permutable_to_palindrome.py
Is an anonymous letter constructible?	is_anonymous_letter_constructible.cc	IsAnonymousLetterConstructible.java	is_anonymous_letter_constructible.py
Implement an ISBN cache	lru_cache.cc	LruCache.java	lru_cache.py
Compute the LCA, optimizing for close ancestors	lowest_common_ancestor_close_ancestor.cc	LowestCommonAncestorCloseAncestor.java	lowest_common_ancestor_close_ancestor.py
Find the nearest repeated entries in an array	nearest_repeated_entries.cc	NearestRepeatedEntries.java	nearest_repeated_entries.py
Find the smallest subarray covering all values	smallest_subarray_covering_set.cc	SmallestSubarrayCoveringSet.java	smallest_subarray_covering_set.py
Find smallest subarray sequentially covering all values	smallest_subarray_covering_all_values.cc	SmallestSubarrayCoveringAllValues.java	smallest_subarray_covering_all_values.py
Find the longest subarray with distinct entries	longest_subarray_with_distinct_values.cc	LongestSubarrayWithDistinctValues.java	longest_subarray_with_distinct_values.py
Find the length of a longest contained interval	longest_contained_interval.cc	LongestContainedInterval.java	longest_contained_interval.py
Compute all string decompositions	string_decompositions_into_dictionary_words.cc	StringDecompositionsIntoDictionaryWords.java	string_decompositions_into_dictionary_words.py
Test the Collatz conjecture	collatz_checker.cc	CollatzChecker.java	collatz_checker.py
Compute the intersection of two sorted arrays	intersect_sorted_arrays.cc	IntersectSortedArrays.java	intersect_sorted_arrays.py
Merge two sorted arrays	two_sorted_arrays_merge.cc	TwoSortedArraysMerge.java	two_sorted_arrays_merge.py
Computing the h-index	h_index.cc	HIndex.java	h_index.py
Remove first-name duplicates	remove_duplicates.cc	RemoveDuplicates.java	remove_duplicates.py
Smallest nonconstructible value	smallest_nonconstructible_value.cc	SmallestNonconstructibleValue.java	smallest_nonconstructible_value.py
Render a calendar	calendar_rendering.cc	CalendarRendering.java	calendar_rendering.py
Merging intervals	interval_add.cc	IntervalAdd.java	interval_add.py
Compute the union of intervals	intervals_union.cc	IntervalsUnion.java	intervals_union.py
Partitioning and sorting an array with many repeated entries	group_equal_entries.cc	GroupEqualEntries.java	group_equal_entries.py
Team photo day - 1	is_array_dominated.cc	IsArrayDominated.java	is_array_dominated.py
Implement a fast sorting algorithm for lists	sort_list.cc	SortList.java	sort_list.py
Compute a salary threshold	find_salary_threshold.cc	FindSalaryThreshold.java	find_salary_threshold.py
Test if a binary tree satisfies the BST property	is_tree_a_bst.cc	IsTreeABst.java	is_tree_a_bst.py
Find the first key greater than a given value in a BST	search_first_greater_value_in_bst.cc	SearchFirstGreaterValueInBst.java	search_first_greater_value_in_bst.py
Find the k largest elements in a BST	k_largest_values_in_bst.cc	KLargestValuesInBst.java	k_largest_values_in_bst.py
Compute the LCA in a BST	lowest_common_ancestor_in_bst.cc	LowestCommonAncestorInBst.java	lowest_common_ancestor_in_bst.py
Reconstruct a BST from traversal data	bst_from_preorder.cc	BstFromPreorder.java	bst_from_preorder.py
Find the closest entries in three sorted arrays	minimum_distance_3_sorted_arrays.cc	MinimumDistance3SortedArrays.java	minimum_distance_3_sorted_arrays.py
Enumerate numbers of the form a + b sqrt(2)	a_b_sqrt2.cc	ABSqrt2.java	a_b_sqrt2.py
Build a minimum height BST from a sorted array	bst_from_sorted_array.cc	BstFromSortedArray.java	bst_from_sorted_array.py
Test if three BST nodes are totally ordered	descendant_and_ancestor_in_bst.cc	DescendantAndAncestorInBst.java	descendant_and_ancestor_in_bst.py
The range lookup problem	range_lookup_in_bst.cc	RangeLookupInBst.java	range_lookup_in_bst.py
Add credits	adding_credits.cc	AddingCredits.java	adding_credits.py
The Towers of Hanoi problem	hanoi.cc	Hanoi.java	hanoi.py
Generate all nonattacking placements of n-Queens	n_queens.cc	NQueens.java	n_queens.py
Generate permutations	permutations.cc	Permutations.java	permutations.py
Generate the power set	power_set.cc	PowerSet.java	power_set.py
Generate all subsets of size k	combinations.cc	Combinations.java	combinations.py
Generate strings of matched parens	enumerate_balanced_parentheses.cc	EnumerateBalancedParentheses.java	enumerate_balanced_parentheses.py
Generate palindromic decompositions	enumerate_palindromic_decompositions.cc	EnumeratePalindromicDecompositions.java	enumerate_palindromic_decompositions.py
Generate binary trees	enumerate_trees.cc	EnumerateTrees.java	enumerate_trees.py
Implement a Sudoku solver	sudoku_solve.cc	SudokuSolve.java	sudoku_solve.py
Compute a Gray code	gray_code.cc	GrayCode.java	gray_code.py
Bootcamp: Dynamic Programming	fibonacci.cc	Fibonacci.java	fibonacci.py
Bootcamp: Dynamic Programming	max_sum_subarray.cc	MaxSumSubarray.java	max_sum_subarray.py
Count the number of score combinations	number_of_score_combinations.cc	NumberOfScoreCombinations.java	number_of_score_combinations.py
Compute the Levenshtein distance	levenshtein_distance.cc	LevenshteinDistance.java	levenshtein_distance.py
Count the number of ways to traverse a 2D array	number_of_traversals_matrix.cc	NumberOfTraversalsMatrix.java	number_of_traversals_matrix.py
Compute the binomial coefficients	binomial_coefficients.cc	BinomialCoefficients.java	binomial_coefficients.py
Search for a sequence in a 2D array	is_string_in_matrix.cc	IsStringInMatrix.java	is_string_in_matrix.py
The knapsack problem	knapsack.cc	Knapsack.java	knapsack.py
The bedbathandbeyond.com problem	is_string_decomposable_into_words.cc	IsStringDecomposableIntoWords.java	is_string_decomposable_into_words.py
Find the minimum weight path in a triangle	minimum_weight_path_in_a_triangle.cc	MinimumWeightPathInATriangle.java	minimum_weight_path_in_a_triangle.py
Pick up coins for maximum gain	picking_up_coins.cc	PickingUpCoins.java	picking_up_coins.py
Count the number of moves to climb stairs	number_of_traversals_staircase.cc	NumberOfTraversalsStaircase.java	number_of_traversals_staircase.py
The pretty printing problem	pretty_printing.cc	PrettyPrinting.java	pretty_printing.py
Find the longest nondecreasing subsequence	longest_nondecreasing_subsequence.cc	LongestNondecreasingSubsequence.java	longest_nondecreasing_subsequence.py
Compute an optimum assignment of tasks	task_pairing.cc	TaskPairing.java	task_pairing.py
Schedule to minimize waiting time	minimum_waiting_time.cc	MinimumWaitingTime.java	minimum_waiting_time.py
The interval covering problem	minimum_points_covering_intervals.cc	MinimumPointsCoveringIntervals.java	minimum_points_covering_intervals.py
The interval covering problem	two_sum.cc	TwoSum.java	two_sum.py
The 3-sum problem	three_sum.cc	ThreeSum.java	three_sum.py
Find the majority element	majority_element.cc	MajorityElement.java	majority_element.py
The gasup problem	refueling_schedule.cc	RefuelingSchedule.java	refueling_schedule.py
Compute the maximum water trapped by a pair of vertical lines	max_trapped_water.cc	MaxTrappedWater.java	max_trapped_water.py
Compute the largest rectangle under the skyline	largest_rectangle_under_skyline.cc	LargestRectangleUnderSkyline.java	largest_rectangle_under_skyline.py
Search a maze	search_maze.cc	SearchMaze.java	search_maze.py
Paint a Boolean matrix	matrix_connected_regions.cc	MatrixConnectedRegions.java	matrix_connected_regions.py
Compute enclosed regions	matrix_enclosed_regions.cc	MatrixEnclosedRegions.java	matrix_enclosed_regions.py
Deadlock detection	deadlock_detection.cc	DeadlockDetection.java	deadlock_detection.py
Clone a graph	graph_clone.cc	GraphClone.java	graph_clone.py
Making wired connections	is_circuit_wirable.cc	IsCircuitWirable.java	is_circuit_wirable.py
Transform one string to another	string_transformability.cc	StringTransformability.java	string_transformability.py
Team photo day - 2	max_teams_in_photograph.cc	MaxTeamsInPhotograph.java	max_teams_in_photograph.py
Compute the greatest common divisor	gcd.cc	Gcd.java	gcd.py
Find the first missing positive entry	first_missing_positive_entry.cc	FirstMissingPositiveEntry.java	first_missing_positive_entry.py
Buy and sell a stock k times	buy_and_sell_stock_k_times.cc	BuyAndSellStockKTimes.java	buy_and_sell_stock_k_times.py
Compute the maximum product of all entries but one	max_product_all_but_one.cc	MaxProductAllButOne.java	max_product_all_but_one.py
Compute the longest contiguous increasing subarray	longest_increasing_subarray.cc	LongestIncreasingSubarray.java	longest_increasing_subarray.py
Rotate an array	rotate_array.cc	RotateArray.java	rotate_array.py
Identify positions attacked by rooks	rook_attack.cc	RookAttack.java	rook_attack.py
Justify text	left_right_justify_text.cc	LeftRightJustifyText.java	left_right_justify_text.py
Implement list zipping	zip_list.cc	ZipList.java	zip_list.py
Copy a postings list	copy_posting_list.cc	CopyPostingList.java	copy_posting_list.py
Compute the longest substring with matching parens	longest_substring_with_matching_parentheses.cc	LongestSubstringWithMatchingParentheses.java	longest_substring_with_matching_parentheses.py
Compute the maximum of a sliding window	max_of_sliding_window.cc	MaxOfSlidingWindow.java	max_of_sliding_window.py
Implement a postorder traversal without recursion	tree_postorder.cc	TreePostorder.java	tree_postorder.py
Compute fair bonuses	bonus.cc	Bonus.java	bonus.py
Search a sorted array of unknown length	search_unknown_length_array.cc	SearchUnknownLengthArray.java	search_unknown_length_array.py
Search in two sorted arrays	kth_largest_element_in_two_sorted_arrays.cc	KthLargestElementInTwoSortedArrays.java	kth_largest_element_in_two_sorted_arrays.py
Find the kth largest element - large n, small k	kth_largest_element_in_long_array.cc	KthLargestElementInLongArray.java	kth_largest_element_in_long_array.py
Find an element that appears only once	element_appearing_once.cc	ElementAppearingOnce.java	element_appearing_once.py
Find the line through the most points	line_through_most_points.cc	LineThroughMostPoints.java	line_through_most_points.py
Convert a sorted doubly linked list into a BST	sorted_list_to_bst.cc	SortedListToBst.java	sorted_list_to_bst.py
Convert a BST to a sorted doubly linked list	bst_to_sorted_list.cc	BstToSortedList.java	bst_to_sorted_list.py
Merge two BSTs	bst_merge.cc	BstMerge.java	bst_merge.py
Implement regular expression matching	regular_expression.cc	RegularExpression.java	regular_expression.py
Synthesize an expression	insert_operators_in_string.cc	InsertOperatorsInString.java	insert_operators_in_string.py
Count inversions	count_inversions.cc	CountInversions.java	count_inversions.py
Draw the skyline	drawing_skyline.cc	DrawingSkyline.java	drawing_skyline.py
Measure with defective jugs	defective_jugs.cc	DefectiveJugs.java	defective_jugs.py
Compute the maximum subarray sum in a circular array	maximum_subarray_in_circular_array.cc	MaximumSubarrayInCircularArray.java	maximum_subarray_in_circular_array.py
Determine the critical height	max_safe_height.cc	MaxSafeHeight.java	max_safe_height.py
Find the maximum 2D subarray	max_submatrix.cc	MaxSubmatrix.java	max_submatrix.py
Find the maximum 2D subarray	max_square_submatrix.cc	MaxSquareSubmatrix.java	max_square_submatrix.py
Implement Huffman coding	huffman_coding.cc	HuffmanCoding.java	huffman_coding.py
Trapping water	max_water_trappable.cc	MaxWaterTrappable.java	max_water_trappable.py
The heavy hitter problem	search_frequent_items.cc	SearchFrequentItems.java	search_frequent_items.py
Find the longest subarray whose sum <= k	longest_subarray_with_sum_constraint.cc	LongestSubarrayWithSumConstraint.java	longest_subarray_with_sum_constraint.py
Road network	road_network.cc	RoadNetwork.java	road_network.py
Test if arbitrage is possible	arbitrage.cc	Arbitrage.java	arbitrage.py

Acknowledgments

A big shout-out to the hundreds of users who tried out the release over the past couple of months. As always, we never fail to be impressed by the enthusiasm and commitment our readers have; it has served to bring out the best in us. We all thank Viacheslav Kroilov, for applying his exceptional software engineering skills to make EPI Judge a reality.