CONY的世界

114. Flatten Binary Tree to Linked List

Given a binary tree, flatten it to a linked list in-place.

764. Largest Plus Sign

In a 2D grid from (0, 0) to (N-1, N-1), every cell contains a 1, except those cells in the given list mines which are 0. What is the largest axis-aligned plus sign of 1s contained in the grid? Return the order of the plus sign. If there is none, return 0.

785. Is Graph Bipartite?

Given a graph, return true if and only if it is bipartite.

670. Maximum Swap

127. Word Ladder

Given two words (beginWord and endWord), and a dictionary's word list, find the length of shortest transformation sequence from beginWord to endWord, such that:

261. Graph Valid Tree

Given n nodes labeled from 0 to n - 1 and a list of undirected edges (each edge is a pair of nodes), write a function to check whether these edges make up a valid tree.

337. House Robber III

The thief has found himself a new place for his thievery again. There is only one entrance to this area, called the "root." Besides the root, each house has one and only one parent house. After a tour, the smart thief realized that "all houses in this place forms a binary tree". It will automatically contact the police if two directly-linked houses were broken into on the same night.

116. Populating Next Right Pointers in Each Node

341. Flatten Nested List Iterator

621. Task Scheduler

Given a char array representing tasks CPU need to do. It contains capital letters A to Z where different letters represent different tasks.Tasks could be done without original order. Each task could be done in one interval. For each interval, CPU could finish one task or just be idle.

56. Merge Intervals

Given a collection of intervals, merge all overlapping intervals.

139. Word Break

Given a non-empty string s and a dictionary wordDict containing a list of non-empty words, determine if s can be segmented into a space-separated sequence of one or more dictionary words. You may assume the dictionary does not contain duplicate words.

236. Lowest Common Ancestor of a Binary Tree 

17. Letter Combinations of a Phone Number

Given a digit string, return all possible letter combinations that the number could represent.

92. Reverse Linked List II

Reverse a linked list from position m to n. Do it in-place and in one-pass.

173. Binary Search Tree Iterator

 29. Divide Two Integers

Divide two integers without using multiplication, division and mod operator.

33. Search in Rotated Sorted Array

Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.

3. Longest Substring Without Repeating Characters

162. Find Peak Element