LeetCode

LeetCode

Solutions to some of the questions on the LeetCode website.

The questions are divided into 3 levels of difficulty:

• Easy
• Medium
• Hard

Solutions

Problem Solution	Problem Statement	Difficulty
LC0001.cpp	Two Sum	Easy
LC0002.cpp	Add Two Numbers	Medium
LC0003.cpp	Longest Substring Without Repeating Characters	Medium
LC0007.cpp	Reverse Integer	Easy
LC0009.cpp	Palindrome Number	Easy
LC0011.cpp	Container With Most Water	Medium
LC0014.cpp	Longest Common Prefix	Easy
LC0015.cpp	3Sum	Medium
LC0020.cpp	Valid Parentheses	Easy
LC0021.cpp	Merge Two Sorted Lists	Easy
LC0031.cpp	Next Permutation	Medium
LC0033.cpp	Search in Rotated Sorted Array	Medium
LC0035.cpp	Search Insert Position	Easy
LC0046.cpp	Permutations	Medium
LC0047.cpp	Permutations II	Medium
LC0049.cpp	Group Anagrams	Medium
LC0050.cpp	Pow(x, n)	Medium
LC0053.cpp	Maximum Subarray	Easy
LC0055.cpp	Jump Game	Medium
LC0057.cpp	Insert Interval	Medium
LC0058.cpp	Length of Last Word	Easy
LC0060.cpp	Permutation Sequence	Medium
LC0062.cpp	Unique Paths	Medium
LC0063.cpp	Unique Paths II	Medium
LC0064.cpp	Minimum Path Sum	Medium
LC0065.cpp	Valid Number	Hard
LC0066.cpp	Plus One	Easy
LC0067.cpp	Add Binary	Easy
LC0069.cpp	Sqrt(x)	Easy
LC0070.cpp	Climbing Stairs	Easy
LC0072.cpp	Edit Distance	Hard
LC0074.cpp	Search a 2D Matrix	Medium
LC0075.cpp	Sort Colors	Medium
LC0078.cpp	Subsets	Medium
LC0079.cpp	Word Search	Medium
LC0081.cpp	Search in Rotated Sorted Array II	Medium
LC0088.cpp	Merge Sorted Array	Easy
LC0089.cpp	Gray Code	Medium
LC0090.cpp	Subsets II	Medium
LC0092.cpp	Reverse Linked List II	Medium
LC0094.cpp	Binary Tree Inorder Traversal	Medium
LC0095.cpp	Unique Binary Search Trees II	Medium
LC0096.cpp	Unique Binary Search Trees	Medium
LC0098.cpp	Validate Binary Search Tree	Medium
LC0100.cpp	Same Tree	Easy
LC0101.cpp	Symmetric Tree	Easy
LC0102.cpp	Binary Tree Level Order Traversal	Medium
LC0103.cpp	Binary Tree Zigzag Level Order Traversal	Medium
LC0104.cpp	Maximum Depth of Binary Tree	Easy
LC0105.cpp	Construct Binary Tree from Preorder and Inorder Traversal	Medium
LC0106.cpp	Construct Binary Tree from Inorder and Postorder Traversal	Medium
LC0107.cpp	Binary Tree Level Order Traversal II	Easy
LC0112.cpp	Path Sum	Easy
LC0118.cpp	Pascal's Triangle	Easy
LC0119.cpp	Pascal's Triangle II	Easy
LC0121.cpp	Best Time to Buy and Sell Stock	Easy
LC0122.cpp	Best Time to Buy and Sell Stock II	Easy
LC0123.cpp	Best Time to Buy and Sell Stock III	Hard
LC0124.cpp	Binary Tree Maximum Path Sum	Hard
LC0126.cpp	Word Ladder II	Hard
LC0127.cpp	Word Ladder	Medium
LC0129.cpp	Sum Root to Leaf Numbers	Medium
LC0130.cpp	Surrounded Regions	Medium
LC0134.cpp	Gas Station	Medium
LC0136.cpp	Single Number	Easy
LC0137.cpp	Single Number II	Medium
LC0138.cpp	Copy List with Random Pointer	Medium
LC0139.cpp	Word Break	Medium
LC0140.cpp	Word Break II	Hard
LC0142.cpp	Linked List Cycle II	Medium
LC0143.cpp	Reorder List	Medium
LC0144.cpp	Binary Tree Preorder Traversal	Medium
LC0146.cpp	LRU Cache	Medium
LC0147.cpp	Insertion Sort List	Medium
LC0151.cpp	Reverse Words in a String	Medium
LC0152.cpp	Maximum Product Subarray	Medium
LC0153.cpp	Find Minimum in Rotated Sorted Array	Medium
LC0154.cpp	Find Minimum in Rotated Sorted Array II	Hard
LC0155.cpp	Min Stack	Easy
LC0162.cpp	Find Peak Element	Medium
LC0165.cpp	Compare Version Numbers	Medium
LC0167.cpp	Two Sum II - Input array is sorted	Easy
LC0168.cpp	Excel Sheet Column Title	Easy
LC0169.cpp	Majority Element	Easy
LC0171.cpp	Excel Sheet Column Number	Easy
LC0174.cpp	Dungeon Game	Hard
LC0179.cpp	Largest Number	Medium
LC0188.cpp	Best Time to Buy and Sell Stock IV	Hard
LC0189.cpp	Rotate Array	Easy
LC0190.cpp	Reverse Bits	Easy
LC0198.cpp	House Robber	Easy
LC0199.cpp	Binary Tree Right Side View	Medium
LC0200.cpp	Number of Islands	Medium
LC0201.cpp	Bitwise AND of Numbers Range	Medium
LC0202.cpp	Happy Number	Easy
LC0203.cpp	Remove Linked List Elements	Easy
LC0207.cpp	Course Schedule	Medium
LC0208.cpp	Implement Trie (Prefix Tree)	Medium
LC0210.cpp	Course Schedule II	Medium
LC0211.cpp	Add and Search Word - Data structure design	Medium
LC0212.cpp	Word Search II	Hard
LC0213.cpp	House Robber II	Medium
LC0215.cpp	Kth Largest Element in an Array	Medium
LC0216.cpp	Combination Sum III	Medium
LC0217.cpp	Contains Duplicate	Easy
LC0219.cpp	Contains Duplicate II	Easy
LC0220.cpp	Contains Duplicate III	Medium
LC0221.cpp	Maximal Square	Medium
LC0222.cpp	Count Complete Tree Nodes	Medium
LC0226.cpp	Invert Binary Tree	Easy
LC0229.cpp	Majority Element II	Medium
LC0230.cpp	Kth Smallest Element in a BST	Medium
LC0231.cpp	Power of Two	Easy
LC0235.cpp	Lowest Common Ancestor of a Binary Search Tree	Easy
LC0236.cpp	Lowest Common Ancestor of a Binary Tree	Medium
LC0237.cpp	Delete Node in a Linked List	Easy
LC0238.cpp	Product of Array Except Self	Medium
LC0242.cpp	Valid Anagram	Easy
LC0258.cpp	Add Digits	Easy
LC0260.cpp	Single Number III	Medium
LC0263.cpp	Ugly Number	Easy
LC0264.cpp	Ugly Number II	Medium
LC0268.cpp	Missing Number	Easy
LC0274.cpp	H-Index	Medium
LC0275.cpp	H-Index II	Medium
LC0278.cpp	First Bad Version	Easy
LC0279.cpp	Perfect Squares	Medium
LC0283.cpp	Move Zeroes	Easy
LC0287.cpp	Find the Duplicate Number	Medium
LC0290.cpp	Word Pattern	Easy
LC0299.cpp	Bulls and Cows	Easy
LC0300.cpp	Longest Increasing Subsequence	Medium
LC0303.cpp	Range Sum Query - Immutable	Easy
LC0307.cpp	Range Sum Query - Mutable	Medium
LC0309.cpp	Best Time to Buy and Sell Stock with Cooldown	Medium
LC0322.cpp	Coin Change	Medium
LC0328.cpp	Odd Even Linked List	Medium
LC0332.cpp	Reconstruct Itinerary	Medium
LC0338.cpp	Counting Bits	Medium
LC0342.cpp	Power of Four	Easy
LC0344.cpp	Reverse String	Easy
LC0347.cpp	Top K Frequent Elements	Medium
LC0367.cpp	Valid Perfect Square	Easy
LC0368.cpp	Largest Divisible Subset	Medium
LC0380.cpp	Insert Delete GetRandom O(1)	Medium
LC0383.cpp	Ransom Note	Easy
LC0387.cpp	First Unique Character in a String	Easy
LC0392.cpp	Is Subsequence	Easy
LC0402.cpp	Remove K Digits	Medium
LC0404.cpp	Sum of Left Leaves	Easy
LC0406.cpp	Queue Reconstruction by Height	Medium
LC0409.cpp	Longest Palindrome	Easy
LC0412.cpp	Fizz Buzz	Easy
LC0421.cpp	Maximum XOR of Two Numbers in an Array	Medium
LC0430.cpp	Flatten a Multilevel Doubly Linked List	Medium
LC0435.cpp	Non-overlapping Intervals	Medium
LC0436.cpp	Find Right Interval	Medium
LC0437.cpp	Path Sum III	Medium
LC0438.cpp	Find All Anagrams in a String	Medium
LC0441.cpp	Arranging Coins	Easy
LC0442.cpp	Find All Duplicates in an Array	Medium
LC0450.cpp	Delete Node in a BST	Medium
LC0451.cpp	Sort Characters By Frequency	Medium
LC0459.cpp	Repeated Substring Pattern	Easy
LC0461.cpp	Hamming Distance	Easy
LC0463.cpp	Island Perimeter	Easy
LC0468.cpp	Validate IP Address	Medium
LC0470.cpp	Implement Rand10() Using Rand7()	Medium
LC0476.cpp	Number Complement	Easy
LC0495.cpp	Teemo Attacking	Medium
LC0497.cpp	Random Point in Non-overlapping Rectangles	Medium
LC0515.cpp	Find Largest Value in Each Tree Row	Medium
LC0518.cpp	Coin Change 2	Medium
LC0520.cpp	Detect Capital	Easy
LC0525.cpp	Contiguous Array	Medium
LC0528.cpp	Random Pick with Weight	Medium
LC0540.cpp	Single Element in a Sorted Array	Medium
LC0543.cpp	Diameter of Binary Tree	Easy
LC0560.cpp	Subarray Sum Equals K	Medium
LC0567.cpp	Permutation in String	Medium
LC0575.cpp	Distribute Candies	Easy
LC0621.cpp	Task Scheduler	Medium
LC0662.cpp	Maximum Width of Binary Tree	Medium
LC0678.cpp	Valid Parenthesis String	Medium
LC0692.cpp	Top K Frequent Words	Medium
LC0700.cpp	Search in a Binary Search Tree	Easy
LC0701.cpp	Insert into a Binary Search Tree	Medium
LC0705.cpp	Design HashSet	Easy
LC0706.cpp	Design HashMap	Easy
LC0714.cpp	Best Time to Buy and Sell Stock with Transaction Fee	Medium
LC0718.cpp	Maximum Length of Repeated Subarray	Medium
LC0733.cpp	Flood Fill	Easy
LC0763.cpp	Partition Labels	Medium
LC0771.cpp	Jewels and Stones	Easy
LC0787.cpp	Cheapest Flights Within K Stops	Medium
LC0797.cpp	All Paths From Source to Target	Medium
LC0824.cpp	Goat Latin	Easy
LC0835.cpp	Image Overlap	Medium
LC0844.cpp	Backspace String Compare	Easy
LC0876.cpp	Middle of the Linked List	Easy
LC0886.cpp	Possible Bipartition	Medium
LC0889.cpp	Construct Binary Tree from Preorder and Postorder Traversal	Medium
LC0901.cpp	Online Stock Span	Medium
LC0905.cpp	Sort Array By Parity	Easy
LC0918.cpp	Maximum Sum Circular Subarray	Medium
LC0922.cpp	Sort Array By Parity II	Easy
LC0949.cpp	Largest Time for Given Digits	Easy
LC0952.cpp	Largest Component Size by Common Factor	Hard
LC0957.cpp	Prison Cells After N Days	Medium
LC0967.cpp	Numbers With Same Consecutive Differences	Medium
LC0969.cpp	Pancake Sorting	Medium
LC0973.cpp	K Closest Points to Origin	Medium
LC0980.cpp	Unique Paths III	Hard
LC0983.cpp	Minimum Cost For Tickets	Medium
LC0986.cpp	Interval List Intersections	Medium
LC0987.cpp	Vertical Order Traversal of a Binary Tree	Medium
LC0993.cpp	Cousins in Binary Tree	Easy
LC0994.cpp	Rotting Oranges	Medium
LC0997.cpp	Find the Town Judge	Easy
LC1008.cpp	Construct Binary Search Tree from Preorder Traversal	Medium
LC1009.cpp	Complement of Base 10 Integer	Easy
LC1022.cpp	Sum of Root To Leaf Binary Numbers	Easy
LC1029.cpp	Two City Scheduling	Easy
LC1035.cpp	Uncrossed Lines	Medium
LC1041.cpp	Robot Bounded In Circle	Medium
LC1044.cpp	Longest Duplicate Substring	Hard
LC1046.cpp	Last Stone Weight	Easy
LC1094.cpp	Car Pooling	Medium
LC1103.cpp	Distribute Candies to People	Easy
LC1143.cpp	Longest Common Subsequence	Medium
LC1190.cpp	Reverse Substrings Between Each Pair of Parentheses	Medium
LC1191.cpp	K-Concatenation Maximum Sum	Medium
LC1201.cpp	Ugly Number III	Medium
LC1202.cpp	Smallest String With Swaps	Medium
LC1208.cpp	Get Equal Substrings Within Budget	Medium
LC1209.cpp	Remove All Adjacent Duplicates in String II	Medium
LC1218.cpp	Longest Arithmetic Subsequence of Given Difference	Medium
LC1219.cpp	Path with Maximum Gold	Medium
LC1222.cpp	Queens That Can Attack the King	Medium
LC1229.cpp	Meeting Scheduler	Medium
LC1230.cpp	Toss Strange Coins	Medium
LC1232.cpp	Check If It Is a Straight Line	Easy
LC1233.cpp	Remove Sub-Folders from the Filesystem	Medium
LC1238.cpp	Circular Permutation in Binary Representation	Medium
LC1239.cpp	Maximum Length of a Concatenated String with Unique Characters	Medium
LC1248.cpp	Count Number of Nice Subarrays	Medium
LC1249.cpp	Minimum Remove to Make Valid Parentheses	Medium
LC1261.cpp	Find Elements in a Contaminated Binary Tree	Medium
LC1262.cpp	Greatest Sum Divisible by Three	Medium
LC1267.cpp	Count Servers that Communicate	Medium
LC1268.cpp	Search Suggestions System	Medium
LC1276.cpp	Number of Burgers with No Waste of Ingredients	Medium
LC1277.cpp	Count Square Submatrices with All Ones	Medium
LC1282.cpp	Group the People Given the Group Size They Belong To	Medium
LC1283.cpp	Find the Smallest Divisor Given a Threshold	Medium
LC1286.cpp	Iterator for Combination	Medium
LC1288.cpp	Remove Covered Intervals	Medium
LC1291.cpp	Sequential Digits	Medium
LC1292.cpp	Maximum Side Length of a Square with Sum Less than or Equal to Threshold	Medium
LC1296.cpp	Divide Array in Sets of K Consecutive Numbers	Medium
LC1297.cpp	Maximum Number of Occurrences of a Substring	Medium
LC1300.cpp	Sum of Mutated Array Closest to Target	Medium
LC1302.cpp	Deepest Leaves Sum	Medium
LC1305.cpp	All Elements in Two Binary Search Trees	Medium
LC1306.cpp	Jump Game III	Medium
LC1310.cpp	XOR Queries of a Subarray	Medium
LC1311.cpp	Get Watched Videos by Your Friends	Medium
LC1314.cpp	Matrix Block Sum	Medium
LC1315.cpp	Sum of Nodes with Even-Valued Grandparent	Medium
LC1318.cpp	Minimum Flips to Make a OR b Equal to c	Medium
LC1319.cpp	Number of Operations to Make Network Connected	Medium
LC1324.cpp	Print Words Vertically	Medium
LC1344.cpp	Angle Between Hands of a Clock	Medium
LC1426.cpp	Counting Elements	Easy
LC1427.cpp	Perform String Shifts	Easy
LC1428.cpp	Leftmost Column with at Least a One	Medium
LC1429.cpp	First Unique Number	Medium
LC1430.cpp	Check If a String Is a Valid Sequence from Root to Leaves Path in a Binary Tree	Medium
LC1467.cpp	Probability of a Two Boxes Having The Same Number of Distinct Balls	Hard
LC1566.cpp	Detect Pattern of Length M Repeated K or More Times	Easy
LC1567.cpp	Maximum Length of Subarray With Positive Product	Medium