今天好好优秀了么

题目 Given two strings s and t, determine if they are isomorphic. Two strings are isomorphic if the characters in s can be replaced to get t. All occurrences of a character must be replaced with anoth...

题目描述 Input: 1 / 2 3 \ 5 Output: [“1->2->5”, “1->3”] Explanation: All root-to-leaf paths are: 1->2->5, 1->3 解题思路： 利用递归，分为三步，输出val，输出左子树，输出右子树。 要到的问题 不知道怎么把数字转换成字符串，尝试过stre...

问题描述 Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the absolute difference between i and j is at mos...

题目描述 Given a pattern and a string str, find if str follows the same pattern. Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in str. I...

题目描述 Write a function that takes a string as input and reverse only the vowels of a string. Example 1: Input: “hello” Output: “holle” Example 2: Input: “leetcode” Output: “leotcede” 刚开始暴力双重循环，然后超时 c...

问题描述 当作回顾一下set的用法吧。 set的常用方法： begin() 　　 返回set容器的第一个迭代器 end() 　　　返回set容器的最后一个迭代器 clear() 　　 删除set容器中的所有的元素 empty() 　　　判断set容器是否为空 max_size() 　 返回set容器可能包含的元素最大个数 size() 　　　　 返回当前set容器中的元素...

题目描述 注：vector没有find函数！！！ 代码如下： class Solution { public: vector<int> intersect(vector<int>& nums1, vector<int>& nums2) { vector<int> v; sort(nums1.b...

问题描述 Given a singly linked list, determine if it is a palindrome. Example 1: Input: 1->2 Output: false Example 2: Input: 1->2->2->1 Output: true Follow up: Could you do it in O(n) time...