87. Scramble String 题目 Given a string s1, we may represent it as a binary tree by partitioning it to two non-e…

72. Edit Distance 题目 要想把字符串S1变成S2，可以经过若干次下列原子操作： 1.删除一个字符 2.增加一个字符 3.更改一个字符 字符串S1和S2的编辑距离定义为从S1变成S2所需要原子操作的最少次…

  All DNA is composed of a series of nucleotides abbreviated as A, C, G, and T, for example: “ACGAA…

Given a binary tree, return the preorder traversal of its nodes’ values. For example:Given binary tree {…

处理字符串类型判断的常见问题 首位空格的处理 //相比较只对字符串的小标进行移动来处理非空序列，这种直接删除的方式后期判断能更快，而且省掉了记录字符首尾下标的麻烦 while(s[0]==' ') s.erase(0,1…

题目描述 输入两棵二叉树A，B，判断B是不是A的子结构。（ps：我们约定空树不是任意一个树的子结构） 解题思路 递归思想，如果根节点相同则递归调用IsSubtree()，如果根节点不相同，则判断root1的左子树和roo…

  Design and implement a TwoSum class. It should support the following operations:add and find. add ̵…

  Given an input string , reverse the string word by word.  Example: Input: ["t","h","e"," ","s…

  Given a binary tree with n nodes, your task is to check if it’s possible to partition t…

  Given a sorted (in ascending order) integer array nums of n elements and …

题目描述 Given a complete binary tree, count the number of nodes. Definition of a complete binary tree from Wikipe…

The set [1,2,3,…,n] contains a total of n! unique permutations. By listing and labeling all of …