7. Reverse Integer

来源：互联网发布：银魂cos淘宝编辑：程序博客网时间：2024/06/05 16:23

题目：Reverse digits of an integer.

Example1: x = 123, return 321

Example2: x = -123, return -321

click to show spoilers.

Note:

The input is assumed to be a 32-bit signed integer. Your function should return 0 when the reversed integer overflows.

class Solution {public:    int reverse(int x) {    }};

我的代码如下，该题比较简单，注意定义result的类型是long long类型

class Solution {public:    int reverse(int x) {        long long flag=1,result=0;        if(x<0)           {flag=-1;x=abs(x);}         while(x)        {            result=result*10+ x%10;            x=x/10;        }        return(flag*result<INT_MIN || flag*result>INT_MAX) ? 0 : flag*result;    }};

其实本题也不用考虑x是否是正负值；代码简化如下：

class Solution {public:    int reverse(int x) {        long long res = 0;        while(x) {            res = res*10 + x%10;            x /= 10;        }        return (res<INT_MIN || res>INT_MAX) ? 0 : res;    }};

1 0