qq_36297981的博客

题目给定两个非空链表来表示两个非负整数。位数按照逆序方式存储，它们的每个节点只存储单个数字。将两数相加返回一个新的链表。你可以假设除了数字 0 之外，这两个数字都不会以零开头。如输入：(2 -> 4 -> 3) + (5 -> 6 -> 4)输出：7 -> 0 -> 8原因：342 + 465 = 807这道题比较简单，不需要什么特殊的算法，...

题目Given a binary tree, return the zigzag level order traversal of its nodes’ values. (ie, from left to right, then right to left for the next level and alternate between).题目大意就是：给定一颗二叉树，第一层从左向右遍历，第...

题目题目太长了：请看链接: Integer To Roman分析有一个简单粗暴的方法就是把0~9, 10 ~ 90, 100 ~ 900, 1000 ~ 3000的组合用数组存起来，然后从里面取就行了代码 string intToRoman(int num) { string M[] = {"", "M", "MM", "MMM"}; string C[...

题目Given two words word1 and word2, find the minimum number of operations required to convert word1 to word2.You have the following 3 operations permitted on a word:Insert a characterDelete a char...

题目Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.Note: You can only move either down or right at...

题目A robot is located at the top-left corner of a m x n grid (marked ‘Start’ in the diagram below).The robot can only move either down or right at any point in time. The robot is trying to reach the ...

题目Given a string containing just the characters'(' and')', find the length of the longest valid (well-formed) parentheses substring.大意就是：给定一个只包含 '('和 ')' 的字符串，找出最长的包含有效括号的子串的长度。示例1：Input: "(()"Ou...

题目Given two binary trees, write a function to check if they are the same or not.Two binary trees are considered the same if they are structurally identical and the nodes have the same value.大意就是判断给...

题目Given a string s, find the longest palindromic substring in s. You may assume that the maximum length of s is 1000.大意就是找到字符串中最大的回文子串，如Input: "babad"Output: "bab"Note: "aba" is also a valid answ...

题目There are two sorted arrays nums1 and nums2 of size m and n respectively.Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).You may assume nums1 and ...

题目The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility)P A H NA P L S I ...

题目Suppose there are n facilities and m customers. We wishto choose:(1) which of the n facilities to open(2) the assignment of customers to facilitiesThe objective is to minimize the sum of the op...