题目: Determine whether an integer is a palindrome. Do this without extra space. click to show spoilers. Some hints: Could negative integers be palindromes? (ie, -1) If you are thinking of converting the integer to string, note the restriction of using…

目录 题目链接 注意点 解法 小结 题目链接 Palindrome Number - LeetCode 注意点 负数肯定是要return false的 数字的位数要分奇数和偶数两种情况 解法 解法一:将数字转化为字符串,然后对字符串从中间开始往两边拓展比较,要分长度为奇数和偶数的情况.时间复杂度为O(n) class Solution { public: bool isPalindrome(int x) { if(x<0 || (x%10 == 0 && x!=0)) { retur…

Palindrome Number time=434ms 负数不是回文数 public class Solution { public boolean isPalindrome(int x) { int palindrome=0; int revers=x; if(revers<0) return false; else{ while(revers>0){ int m=revers%10; palindrome=m+palindrome*10; revers=revers/10; } if(p…

题目: Given a digit string, return all possible letter combinations that the number could represent. A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit string "23" Output: ["ad", "ae"…

Determine whether an integer is a palindrome. Do this without extra space. Some hints: Could negative integers be palindromes? (ie, -1) If you are thinking of converting the integer to string, note the restriction of using extra space. You could also…

问题描述: Write a program to check whether a given number is an ugly number. Ugly numbers are positive numbers whose prime factors only include 2, 3, 5. For example, 6, 8 are ugly while 14 is not ugly since it includes another prime factor 7. Note that 1…

问题描述: Given an array of integers, every element appears twice except for one. Find that single one. Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory? 要求:采用线性时间复杂度,并且最好不使用多余的空间. 一.位操作 异或运算,…

题目: Given a string s, partition s such that every substring of the partition is a palindrome. Return all possible palindrome partitioning of s. For example, given s = "aab", Return [ ["aa","b"], ["a","a",&…

题目: Validate if a given string is numeric. Some examples: "0" => true " 0.1 " => true "abc" => false "1 a" => false "2e10" => true Note: It is intended for the problem statement to be ambigu…

我现在在做一个叫<leetbook>的开源书项目,把解题思路都同步更新到github上了,需要的同学可以去看看 地址:https://github.com/hk029/leetcode 这个是书的地址:https://hk029.gitbooks.io/leetbook/ 009. Palindrome Number[E] 问题: Determine whether an integer is a palindrome. Do this without extra space. 思路 这里说不…