题目： Given a 2D board and a word, find if the word exists in the grid. The word can be constructed from letters…

  Invert a binary tree. 4 / \ 2 7 / \ / \ 1 3 6 9 to 4 / \ 7 2 / \ / \ 9 6 3 1 Trivia: This problem was i…

  Consider the string s to be the infinite wraparound string of “abcdefghijklmnopqrstuvwx…

  You need to construct a string consists of parenthesis and integers from a binary tree with the preorde…

题目： Given a string s, partition s such that every substring of the partition is a palindrome. R…

题目： Given an array and a value, remove all instances of that value in place and return the new length. The ord…

Given an array of n positive integers and a positive integer s, find the minimal length of a contiguous subarr…

题目地址：https://leetcode-cn.com/probl…题目描述：对于一个具有树特征的无向图，我们可选择任何一个节点作为根。图因此可以成为树，在所有可能的树中，具有最小高度的树被称为最小高度树。…

  Implement pow(x, n), which calculates x raised to the power n(xn). Example 1: …

  Given an unsorted array return whether an increasing subsequence of length 3 exists or not in the array…

  Given a non-empty string containing an out-of-order English representation of digits 0-9…

21. Merge Two Sorted Lists 题目 Merge two sorted linked lists and return it as a new list. The new list should b…