题目描述: 解题思路: 求回文数,并且要求不能使用额外的空间.思路很简单,算出x的倒置数reverse,比较reverse是否和x相等就行了. Java代码: public class LeetCode9 { public static void main(String[] args) { int x=1221; System.out.println(x+"是否是回文数:"+new Solution2().isPalindrome(x)); } } class Solution2 {…

题目简述: 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 coul…

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…

问题链接:https://leetcode.com/problems/palindrome-number/#/description Question:Determine whether an integer is a palindrome. Do this without extra space. 题意:判断一个数是否是回文数,不使用额外的空间. 分析:直接算出数字的倒序与该数字比较即可. 代码: C++版 class Solution { public: bool isPalindrome(…

Determine whether an integer is a palindrome. Do this without extra space. 判断一个整数是不是回文整数(例12321).不能使用多余的空间. Some hints: Could negative integers be palindromes? (ie, -1) If you are thinking of converting the integer to string, note the restriction of…

思路:除和求余 取得首位和末尾 比较是否相等. public boolean isPalindrome(int x){ if(x<0){ return false; } int div=1; while(x/div>=10){ div*=10; } while(x!=0){ int left=x/div; int right=x%10; if(left!=right){ return false; } x=(x%div)/10;//去掉最高位和最低位 div/=100; } return tr…

这道题是LeetCode里的第9道题. 题目说的: 判断一个整数是否是回文数.回文数是指正序(从左向右)和倒序(从右向左)读都是一样的整数. 示例 1: 输入: 121 输出: true 示例 2: 输入: -121 输出: false 解释: 从左向右读, 为 -121 . 从右向左读, 为 121- .因此它不是一个回文数. 示例 3: 输入: 10 输出: false 解释: 从右向左读, 为 01 .因此它不是一个回文数. 进阶: 你能不将整数转为字符串来解决这个问题吗? 这道题虽然简单…

[POJ2104][HDU2665]K-th Number Description You are working for Macrohard company in data structures department. After failing your previous task about key insertion you were asked to write a new data structure that would be able to return quickly k-th…

[SPOJ]NUMOFPAL - Number of Palindromes(Manacher,回文树) 题面 洛谷 求一个串中包含几个回文串 题解 Manacher傻逼题 只是用回文树写写而已.. #include<iostream> #include<cstdio> #include<cstdlib> #include<cstring> #include<cmath> #include<algorithm> #include<…

[CF932G]Palindrome Partition(回文树,动态规划) 题面 CF 翻译: 给定一个串,把串分为偶数段 假设分为了\(s1,s2,s3....sk\) 求,满足\(s_1=s_k,s_2=s_{k-1}......\)的方案数 题解 反正我是不会做 基本就是照着\(laofu\)的打了一遍(laofu太强啦) 这题分成了两个步骤 如果直接分\(k\)段我们是没法直接判断的 假设两段\(s_i,s_{k-i+1}\) 因为\(s_i=s_{k-i+1}=x_1x_2.....…