majesty_的专栏

Reverse bits of a given 32 bits unsigned integer.For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 964176192 (represented in binary as 00111001011110

Given a string S, find the longest palindromic substring in S. You may assume that the maximum length of S is 1000, and there exists one unique longest palindromic substring.求字符串的最长回文串1，从字符串第一个字符开始遍历，向

Given a string, find the length of the longest substring without repeating characters. For example, the longest substring without repeating letters for “abcabcbb” is “abc”, which the length is 3. For “

Given a string S and a string T, count the number of distinct subsequences of T in S.A subsequence of a string is a new string which is formed from the original string by deleting some (can be none) of

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 another chara

Given a binary search tree (BST), find the lowest common ancestor (LCA) of two given nodes in the BST.According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two

Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors.OJ’s undirected graph serialization:Nodes are labeled uniquely. We use # as a separator for each node, an

Write a function to find the longest common prefix string amongst an array of strings. 找所有字符串的公共前缀，简单地实现题class Solution {public: string strPrefix(string s1,string s2){ if(s1.length()==0||s

Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.According to the definition of LCA on Wikipedia: “The lowest common ancestor is defined between two nodes v and

Given two numbers represented as strings, return multiplication of the numbers as a string.Note: The numbers can be arbitrarily large and are non-negative.经典的大数相乘问题： 1，从给定字符串最后一位开始操作，要弄清楚整个乘法的过程以及各进位的

Write an algorithm to determine if a number is “happy”.A happy number is a number defined by the following process: Starting with any positive integer, replace the number by the sum of the squares of i

reverse a singly linked list 题目比较简单，就是反转一个链表.要求用iteratively （迭代）和recursively（递归）解决/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNo

Given a binary tree, return the preorder traversal of its nodes’ values.For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3].Note: Recursive solution is trivial,

Given a binary tree, return the postorder traversal of its nodes’ values.For example: Given binary tree {1,#,2,3},1 \ 2 / 3return [3,2,1]. Note: Recursive solution is trivial, cou

Reverse a linked list from position m to n. Do it in-place and in one-pass. For example: Given 1->2->3->4->5->NULL, m = 2 and n = 4, return 1->4->3->2->5->NULL. Note: Given m, n satisfy the followi

Given a binary tree, return the inorder traversal of its nodes’ values.For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,3,2].Note: Recursive solution is trivial,

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 N A P L

Given an absolute path for a file (Unix-style), simplify it.For example, path = “/home/”, => “/home” path = “/a/./b/../../c/”, => “/c”click to show corner cases. Corner Cases:Did you consider the ca

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 any

Given two words word1 and word2, find the minimum number of steps required to convert word1 to word2. (each operation is counted as 1 step.)You have the following 3 operations permitted on a word:a) In

Given a singly linked list, determine if it is a palindrome.Follow up: Could you do it in O(n) time and O(1) space?判断给定的链表是不是回文的：把要判断的链表分成两部分，将第二部分逆置，逐个与前一部分的val相比较，若不同返回false/** * Definition for sin