摘要： Binary Tree Upside DownGiven a binary tree where all the right nodes are either leaf nodes with a sibling (a left node that shares the same parent nod... 阅读全文

摘要： Excel Sheet Column NumberRelated to questionExcel Sheet Column TitleGiven a column title as appear in an Excel sheet, return its corresponding column ... 阅读全文

摘要： Longest Substring with At Most Two Distinct CharactersGiven a string, find the length of the longest substring T that contains at most 2 distinct char... 阅读全文

摘要： 1、相同点：回溯法在实现上也是遵循深度优先的，即一步一步往前探索，而不像广度优先那样，由近及远一片一片地扫。2、不同点（1）访问序深度优先遍历： 目的是“遍历”，本质是无序的。也就是说访问次序不重要，重要的是都被访问过了。可以参见题Surrounded Regions，深度优先只需要把从边界起始的... 阅读全文

摘要： 1、使用结构体grid作为map的keystruct grid{ int x; int y;};（1）需要自定义比较函数operator &,const std::deque &)”: 未能从“const grid”为“const std::deque &”推导 模板 参数（2）需要定义... 阅读全文

摘要： Median of Two Sorted ArraysThere are two sorted arrays A and B of size m and n respectively. Find the median of the two sorted arrays. The overall run... 阅读全文

摘要： Longest Substring Without Repeating CharactersGiven a string, find the length of the longest substring without repeating characters. For example, the ... 阅读全文

摘要： Add Two NumbersYou are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes co... 阅读全文

摘要： Longest Palindromic SubstringGiven a stringS, find the longest palindromic substring inS. You may assume that the maximum length ofSis 1000, and there... 阅读全文

摘要： ZigZag ConversionThe string"PAYPALISHIRING"is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern i... 阅读全文