Reverse Integer

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

// ConsoleApplication2.cpp: 定义控制台应用程序的入口点。
//

#include "stdafx.h"
#include<math.h>
#include<malloc.h>
int main()
{
	printf("%d\n", sizeof(int));
	int reverse(int x);
	printf("%d",reverse(-1534236421));
    return 0;
}
/*
传入大于int的数会溢出，翻转时大于整形也会溢出
*/
int reverse(int x) {
	int temp = 0,flag=0;
	if (x < 0) {
		temp = -x;
		flag = 1;
	}
	else temp = x;
	int sum=0,temp1=0;
	while (temp){
		int i = 0;
		sum = 0;
		for (i; i < 10; i++) {
			sum = sum + temp1;
			if (sum < temp1)
				return 0;
		}
		
		sum = sum + temp % 10;
		temp /= 10;
		temp1 = sum;
	}
	if (flag) return -sum;
	return sum;
}