Solutions to Leetcode Online Judge
|#|Title|Difficulty| |---|-----|----------| |373|Find K Pairs with Smallest Sums|Medium| |372|Super Pow|Medium| |371|Sum of Two Integers|Easy| |370|Range Addition|Medium| |369|Plus One Linked List|Medium| |368|Largest divisible subset|Medium| |367|Valid Perfect Square|Medium| |366|Find Leaves of Binary Tree|Medium| |365|Water and Jug Problem|Medium| |364|Nested List Weight Sum II|Medium| |363|Max Sum of Rectangle No Larger Than K|Hard| |362|Design Hit Counter|Medium| |361|Bomb Enemy|Medium| |360|Sort Transformed Array|Medium| |359|Logger Rate Limiter|Easy| |358|Rearrage String K distance Apart|Hard| |357|Count Numbers with Unique Digits|Medium| |356|Line Reflection|Medium| |355|Design Twitter|Medium| |354|Russian Doll Envelopes|Hard| |353|Design Snake Game|Medium| |352|Data Stream as Disjoint Intervals|Hard| |351|Android unlock patterns|Medium| |350|Intersection of Two Arrays II|Easy| |349|Intersection of Two Arrays|Easy| |348|Design tic-tac-toe|Medium| |347|Top K frequent elements|Medium| |346|Moving Average from data stream|Easy| |345|Reverse Vowels of a String|Easy| |344|Reverse String|Easy| |343|Integer Break|Medium| |342|Power of Four|Easy| |341|Flatten Nested List Iterator|Medium| |340|Longest Substring with At Most K Distinct Characters|Hard| |339|Nested List Weight Sum|Easy| |338|Counting Bits|Medium| |337|House Robber III|Medium| |336|Palindrome Pairs|Hard| |335|Self Crossing|Hard| |334|Increasing Triplet Subsequence|Medium| |333|Largest BST subtree|Medium| |332|Reconstruct Itinerary|Medium| |331|Verify Preorder Serialization of a Binary Tree|Medium| |330|Patching Array|Medium| |329|Longest Increasing Path in a Matrix|Hard| |328|Odd Even Linked List|Easy| |327|Count of Range Sum|Hard| |326|Power of Three|Easy| |325|Maximum Size Subarray Sum Equals k|Easy| |324|Wiggle Sort II|Medium| |323|Number of Connected Components|Medium| |322|Coin Change|Medium| |321|Create Maximum Number|Hard| |320|Generalized Abbreviation|Medium| |319|Bulb Switcher|Medium| |318|Maximum Product of Word Lengths|Medium| |317|Shortest Distance from All Buildings|Hard| |316|Remove Duplicate Letters|Medium| |315|Count of Smaller Numbers After Self|Hard| |314|Binary Tree Vertical Order Traversal|Medium| |313|Super Ugly Number|Medium| |312|Burst Balloons|Medium| |311|Sparse Matrix Multiplication|Medium| |310|Minimum Height Trees|Medium| |309|Best Time to Buy and Sell Stock with Cooldown|Medium| |308|Range Sum Query 2D - Mutable|Hard| |307|Range Sum Query - Mutable|Medium| |306|Additive Number|Medium| |305|Number of Islands II|Hard| |304|Range Sum Query 2D - Immutable|Medium| |303|Range Sum Query - Immutable|Easy| |302|Smallest Rectangle Enclosing Black Pixels|Hard| |301|Remove Invalid Parentheses|Hard| |300|Longest Increasing Subsequence|Medium| |299|Bulls and Cows|Easy| |298|Binary Tree Longest Consecutive Sequence|Medium| |297|Serialize and Deserialize Binary Tree|Medium| |296|Best Meeting Point|Hard| |295|Find Median from Data Stream|Hard| |294|Flip Game II|Medium| |293|Flip Game|Easy| |292|Nim Game|Easy| |291|Word Pattern II|Hard| |290|Word Pattern|Easy| |289|Game of Life|Medium| |288|Unique Word Abbreviation|Easy| |287|Find the Duplicate Number|Hard| |286|Walls and Gates|Medium| |285|Inorder Successor in BST|Medium| |284|Peeking Iterator|Medium| |283|Moving Zeroes|Easy| |282|Expression Add Operators|Hard| |281|Zigzag Iterator|Medium| |280|Wiggle Sort|Medium| |279|Perfect Squares|Medium| |278|First Bad Version|Easy| |277|Find the Celebrity|Medium| |276|Paint Fence|Easy| |275|H Index II|Medium| |274|H Index|Medium| |273|Integer to English Words|Medium| |272|Closest Binary Search Tree Value II|Hard| |271|Encode and Decode Strings|Medium| |270|Closest Binary Search Tree Value|Easy| |269|Alien Dictionary|Hard| |268|Missing Number|Medium| |267|Palindrome Permutation II|Medium| |266|Palindrome Permutation|Easy| |265|Paint House II|Hard| |264|Ugly Number II|Medium| |263|Ugly Number|Easy| |261|Graph Valid Tree|Medium| |260|Single Number III|Medium| |259|3Sum Smaller|Medium| |258|Add Digits|Easy| |257|Binary Tree Paths|Easy| |256|Paint House|Medium| |255|Verify Preorder Sequence in Binary Search Tree|Medium| |254|Factor Combinations|Medium| |253|Meeting Rooms II|Medium| |252|Meeting Rooms|Easy| |251|Flatten 2D Vector|Medium| |250|Count Univalue Subtrees|Medium| |249|Group Shifted Strings|Easy| |248|Strobogrammatic Number III|Hard| |247|Strobogrammatic Number II|Medium| |246|Strobogrammatic Number|Easy| |245|Shortest Word Distance III|Medium| |244|Shortest Word Distance II|Medium| |243|Shortest Word Distance|Easy| |242|Valid Anagram|Easy| |241|Different Ways to Add Parentheses|Medium| |240|Search a 2D Matrix II|Medium| |239|Sliding Window Maximum|Hard| |238|Product of Array Except Self|Medium| |237|Delete Node in a Linked List|Easy| |236|Lowest Common Ancestor of a Binary Tree|Medium| |235|Lowest Common Ancestor of a Binary Search Tree|Easy| |234|Palindrome Linked List|Easy| |233|Number of Digit One|Medium| |232|Implement Queue using Stacks|Easy| |231|Power of Two|Easy| |230|Kth Smallest Element in a BST|Medium| |229|Majority Element II|Medium| |228|Summary Ranges|Easy| |227|Basic Calculator II|Medium| |226|Invert Binary Tree|Easy| |225|Implement Stack using Queues|Medium| |224|Basic Calculator|Medium| |223|Rectangle Area|Easy| |222|Count Complete Tree Nodes|Medium| |221|Maximal Square|Medium| |220|Contains duplicate iii|Medium| |219|Contains duplicate ii|Easy| |218|The Skyline Problem |Hard| |217|Contains duplicate|Easy| |216|Combination Sum III|Medium| |215|Kth Largest Element in an Array |Medium| |214|Shortest Palindrome|Hard| |213|House robber II|Medium| |212|Word search II|Hard| |211|Add and Search Word|Medium| |210|Course schedule II|Medium| |209|Minimum Size Subarray Sum |Medium| |208|Implement Trie|Medium| |207|Course schedule|Medium| |205|Revese linkedlist|Easy| |205|Isomorphic Strings|Easy| |204|Count primes|Medium| |203|Remove Linked List Elements|Easy| |202|Happy Number|Easy| |201|Bitwise AND of Numbers Range|Medium| |200|Number of islands|Medium| |199|Binary tree right side view|Medium| |198|House robber|Easy| |191|Number of 1 bits|Easy| |190|Reverse bits|Easy| |189|Rotate array|Easy| |188|Best Time to Buy and Sell Stock IV|Hard| |187|Repeated DNA Sequences|Medium| |176|Reverse Words in a String II|Medium| |179|Largest Number|Medium| |174|Dungeon Game|Hard| |173|Binary Search Tree Iterator|Medium| |172|Factorial Trailing Zeroes|Easy| |171|Excel Sheet Column Number|Easy| |169|Majority Element|Easy| |168|Excel Sheet Column Title|Easy| |166|Fraction to Recurring Decimal|Medium| |165|Compare Version Numbers|Easy| |164|Maximum Gap|Hard| |163|Missing Ranges|Medium| |162|Find Peak Element|Medium| |161|One Edit Distance|Medium| |160|Intersection of Two Linked Lists|Easy| |159|Longest Substring with At Most Two Distinct Characters|Hard| |158|Read N Characters Given Read4 II - Call multiple times|Hard| |157|Read N Characters Given Read4|Easy| |156|Binary Tree Upside Down|Medium| |155|Min Stack|Easy| |154|Find Minimum in Rotated Sorted Array II|Hard| |153|Find Minimum in Rotated Sorted Array|Medium| |152|Maximum Product Subarray|Medium| |151|Reverse Words in a String|Medium| |150|Evaluate Reverse Polish Notation|Medium| |149|Max Points on a Line|Hard| |148|Sort List|Medium| |147|Insertion Sort List|Medium| |146|LRU Cache|Hard| |145|Binary Tree Postorder Traversal|Hard| |144|Binary Tree Preorder Traversal|Medium| |143|Reorder List|Medium| |142|Linked List Cycle II|Medium| |141|Linked List Cycle|Medium| |140|Word Break II|Hard| |139|Word Break|Medium| |138|Copy List with Random Pointer|Hard| |137|Single Number II|Medium| |136|Single Number|Medium| |135|Candy|Hard| |134|Gas Station|Medium| |133|Clone Graph|Medium| |132|Palindrome Partitioning II|Hard| |131|Palindrome Partitioning|Medium| |130|Surrounded Regions|Medium| |129|Sum Root to Leaf Numbers|Medium| |128|Longest Consecutive Sequence|Hard| |127|Word Ladder II|Hard| |126|Word Ladder|Medium| |125|Valid Palindrome|Easy| |124|Binary Tree Maximum Path Sum|Hard| |123|Best Time to Buy and Sell Stock III|Hard| |122|Best Time to Buy and Sell Stock II|Medium| |121|Best Time to Buy and Sell Stock|Medium| |120|Triangle|Medium| |119|Pascal's Triangle II|Easy| |118|Pascal's Triangle|Easy| |117|Populating Next Right Pointers in Each Node II|Hard| |116|Populating Next Right Pointers in Each Node|Medium| |115|Distinct Subsequences|Hard| |114|Flatten Binary Tree to Linked List|Medium| |113|Path Sum II|Medium| |112|Path Sum|Easy| |111|Minimum Depth of Binary Tree|Easy| |110|Balanced Binary Tree|Easy| |109|Convert Sorted List to Binary Search Tree|Medium| |108|Convert Sorted Array to Binary Search Tree|Medium| |107|Binary Tree Level Order Traversal II|Easy| |106|Construct Binary Tree from Inorder and Postorder|Medium| |105|Construct Binary Tree from Preorder and Inorder|Medium| |104|Maximum Depth of Binary Tree|Easy| |103|Binary Tree Zigzag Level Order Traversal|Medium| |102|Binary Tree Level Order Traversal|Easy| |101|Symmetric Tree|Easy| |100|Same Tree|Easy| |99|Recover Binary Search Tree|Hard| |98|Validate Binary Search Tree|Medium| |97|Interleaving String|Hard| |96|Unique Binary Search Trees II|Medium| |95|Unique Binary Search Trees|Medium| |94|Binary Tree Inorder Traversal|Medium| |93|Restore IP Addresses|Medium| |92|Reverse linked List II|Medium| |91|Subsets II|Medium| |90|Decode Ways|Medium| |89|Gray Code|Medium| |88|Merge Sorted Array|Easy| |87|Scramble String|Hard| |86|Partition List|Medium| |85|Maximal Rectangle|Hard| |84|Largest Rectangle in Histogram|Hard| |83|Remove Duplicates from Sorted List II|Medium| |82|Remove Duplicates from Sorted List|Easy| |81|Search in Rotated Sorted Array II|Medium| |80|Remove Duplicates from Sorted Array II|Medium| |79|Word Search|Medium| |78|Subsets|Medium| |77|Combinations|Medium| |76|Minimum Window Substring|Hard| |75|Sort Colors|Medium| |74|Search a 2D Matrix|Medium| |73|Set Matrix Zeroes|Medium| |72|Edit Distance|Hard| |71|Simplify Path|Medium| |70|Climbing Stairs|Easy| |69|Sqrt(x)|Medium| |68|Text Justification|Hard| |67|Plus One|Easy| |66|Valid Number|Easy| |65|Add Binary|Easy| |64|Merge Two Sorted Lists|Easy| |63|Minimum Path Sum|Medium| |62|Unique Paths II|Medium| |61|Unique Paths|Medium| |60|Rotate List|Medium| |59|Permutation Sequence|Medium| |58|Spiral Matrix II|Medium| |57|Length of Last Word|Easy| |56|Insert Interval|Hard| |55|Merge Intervals|Hard| |54|Jump Game|Medium| |53|Spiral Matrix|Medium| |52|Maximum Subarray|Medium| |51|N-Queens II|Hard| |50|N-Queens|Hard| |49|"Pow(x, n)"|Medium| |48|Anagrams|Medium| |47|Rotate Image|Medium| |46|Permutations II|Hard| |45|Permutations|Medium| |44|Jump Game II|Hard| |43|Wildcard Matching|Hard| |41|Trapping Rain Water|Hard| |40|First Missing Positive|Hard| |39|Combination Sum II|Medium| |38|Combination Sum|Medium| |37|Count and Say|Easy| |36|Sudoku Solver|Hard| |35|Valid Sudoku|Easy| |34|Search Insert Position|Medium| |33|Search for a Range|Medium| |31|Longest Valid Parentheses|Hard| |32|Search in Rotated Sorted Array|Hard| |30|Next Permutation|Medium| |29|Substring with Concatenation of All Words|Hard| |28|Divide Two Integers|Medium| |27|Implement strStr()|Easy| |26|Remove Element|Easy| |25|Remove Duplicates from Sorted Array|Easy| |24|Reverse Nodes in k-Group|Hard| |23|Swap Nodes in Pairs|Medium| |22|Merge k Sorted Lists|Hard| |21|Generate Parentheses|Medium| |20|Valid Parentheses|Easy| |19|Remove Nth Node From End of List|Easy| |18|Letter Combinations of a Phone Number|Medium| |17|4Sum|Medium| |16|3Sum Closest|Medium| |15|3Sum|Medium| |14|Longest Common Prefix|Easy| |13|Roman to Integer|Easy| |12|Integer to Roman|Medium| |11|Container With Most Water|Medium| |10|Regular Expression Matching|Hard| |9|Palindrome Number|Easy| |8|String to Integer (atoi)|Easy| |7|Reverse Integer|Easy| |6|ZigZag Conversion|Easy| |5|Longest Palindromic Substring|Medium| |4|Median of Two Sorted Arrays|Hard| |3|Longest Substring Without Repeating Characters|Medium| |2|Add Two Numbers|Medium| |1|Two Sum|Medium|