7. Reverse Integer Easy Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 Note: Assume we are dealing with an environment which could on…

题目来源:https://leetcode.com/problems/reverse-integer/ Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 解题思路: 其实这道题看起来非常简单,要实现也是几行代码的事.但是有个小问题容易被忽略,就是边界问题.什么意思呢?如果我们输入的整数超出了int的表达范围,这个问题要怎么解决呢? 用比int更大的数据类型存储我们转…

Reverse Integer Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 click to show spoilers. Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have alread…

Reverse Integer 想用余10直接算,没想到 -123%10 是 7, 原因 -123-(-123//10*10) r=a-n*[a/n] 以上,r是余数,a是被除数,n是除数. 唯一不同点,就是商向0或负无穷方向取整的选择,c从c99开始规定向0取整,python则规定向负无穷取整,选择而已. 所以套用上述公式为: C 语言:(a%n的符号与a相同) -9%7=-9 - 7*[-1]=-2: 9%-7=9 - -7*[-1]=2; Python语言::(a%n的符号与n相同) -9…

原题 水题 唯一注意的点就是数字溢出 class Solution { public: int reverse(int x) { long long MAX = ((long long)1 << 31) - 1; long long MIN = 0 - (1 << 31); long long a = 0; while (x) { a = a * 10 + x % 10; x /= 10; } return a > MAX || a < MIN ? 0 : a; } }…

so easy,注意一下输入不爆int但是反转以后可能爆int. class Solution { public: int gao(int w){ ) ; else{ ; while(w--){ ans*=; } return ans; } } int reverse(int x) { vector<int>v; ){ int t=x; ){ v.push_back(t%); t/=; } ; int siz=v.size(); ; ;i<siz;i++){ ans+=(long lon…

这道题是LeetCode里的第7道题. 题目描述: 给出一个 32 位的有符号整数,你需要将这个整数中每位上的数字进行反转. 示例 1: 输入: 123 输出: 321  示例 2: 输入: -123 输出: -321 示例 3: 输入: 120 输出: 21 注意: 假设我们的环境只能存储得下 32 位的有符号整数,则其数值范围为 [−231,  231 − 1].请根据这个假设,如果反转后整数溢出那么就返回 0. 首先,这是一道简单题,根据我多年的做题经验来看,这道题肯定有坑,绝对会有 IN…

Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 Note:Assume we are dealing with an environment which could only hold integers within t…

题意:将整数倒置,该题简单但是需要注意数据的范围,难得的好题. 如果出现1000000003或者-2000000003,倒置后的数超过int的范围,因此返回0,出现这种情况可以使用long long,也可以在在乘以10时进行判断. 注意:Leetcode是用linux环境的,所以他用的是g++4.78编译器,不是vc++编译器,为此在vc++编译器上我们用__int64,而g++编译器就是long long,这些是64位的int,很有用的东西,不做过相关的竞赛或者项目的人,大部分人都不知道C++…

Question:Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have already thought through this! If the…

# -*- coding: utf8 -*-'''__author__ = 'dabay.wang@gmail.com'https://oj.leetcode.com/problems/reverse-integer/ Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 Have you thought about this?Here are some good qu…

题目: Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123Output: 321 Example 2: Input: -123Output: -321 Example 3: Input: 120Output: 21 Note:Assume we are dealing with an environment which could only store integers within…

Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 Note: Assume we are dealing with an environment which could only store integers within…

Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 Note: Assume we are dealing with an environment which could only hold integers within…

Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 Note:Assume we are dealing with an environment which could only store integers within…

Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have already thought through this! If the integer'…

https://leetcode.com/problems/reverse-integer/ class Solution { public: int inf = ~0u >> 1; int reverse(int x) { if(x == 0)return 0; long long tx = x; long long ans = 0; for(int i = 0;tx;i++){ ans = ans * 10 + tx % 10; tx /= 10; } return int(ans) ==…

Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 总结:处理整数溢出的方法 ①用数据类型转换long  或 long long ②在每次循环时先保存下数字变化之前的值,处理后单步恢复看是否相等 (比③好) ③整体恢复,看数字是否相等. 思路:注意30000这样以0结尾的数字,注意越界时返回0. 我检查越界是通过把翻转的数字再翻转回去,看是否相等. int rever…

题目描述: Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 很简单的题目其实用个数组就能解决了,不过用了一下queue,注意负数的情况. class Solution { public: int reverse(int x) { bool flg=false; ){ flg=true; x=-x; } queue<int> a; ){ a.push(x%); x…

Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 解题思路:将数字翻转并不难,可以转成String类型翻转,也可以逐位翻转,本题涉及到的主要是边界和溢出问题,使用Long或者BigInteger即可解决. 题目不难: JAVA实现如下: public class Solution { static public int reverse(int x) { if(x=…

问题描述: Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have already thought through this! If the in…

problem: Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 thinking: (1)整型反转直观非常easy理解. 如正负,尾数为0等问题还优点理. (2)反转溢出问题要细致处理. code: class Solution { public: int reverse(int x) { long long int y=x; bool flag=true;…

题目: Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 click to show spoilers. Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have already thought t…

Given a 32-bit signed integer, reverse digits of an integer. Example 1: Input: 123 Output: 321 Example 2: Input: -123 Output: -321 Example 3: Input: 120 Output: 21 题意: 给定一个10进制整数,翻转它. Solution1: directly do the simulation. Two tricky parts to be hand…

public int reverse(int x) { long res = 0; while (x != 0){ res = res* 10 + x % 10; x /= 10; } if(res >= Integer.MAX_VALUE || res < Integer.MIN_VALUE) return 0; return (int)res; }…

一.题目链接:https://leetcode.com/problems/reverse-integer/ 二.题目大意: 给定一个整数,要求反转该整数之后再返回:如果归返回的整数超过了int型整数的表示范围,则返回0.例如:输入123,返回321. 三.题解: 这道题目在思路上并不难,主要还是在代码的实现上,这里我主要有两种实现方式. 方法1:将数字转换成字符串,然后计算出该字符串的长度,根据长度和字符来生成一个反转后的数字.代码如下: class Solution { public: int…

题目 Reverse digits of an integer. Example1: x = 123, return 321 Example2: x = -123, return -321 Have you thought about this? Here are some good questions to ask before coding. Bonus points for you if you have already thought through this! If the integ…

A. Bear and Reverse Radewoosh 题目连接: http://www.codeforces.com/contest/658/problem/A Description Limak and Radewoosh are going to compete against each other in the upcoming algorithmic contest. They are equally skilled but they won't solve problems in…

Reverse digits of an integer. Example1: x = , return Example2: x = -, return - 题目意思:对一个整型进行反转 实现代码: class Solution { func reverse(_ x: Int) -> Int { var resultX: Int = 0 var tmp: Int = abs(x) // 求x的绝对值 var str:String = "" if x == 0 { return 0…

潜在问题:(1)随着求和可能精度会溢出int 范围,需要使用long 来辅助判断是否溢出,此时返回 0 Assume we are dealing with an environment which could only store integers within the 32-bit signed integer range: [−231,  231 − 1]. For the purpose of this problem, assume that your function returns…