[Leetcode] #7 Reverse Integer

Discription:

Reverse digits of an integer.

Example1: x = 123, return 321
Example2: x = -123, return -321

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Note:

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

Solution:

int reverse(int x) {
long long rev = 0;           //更换数据类型
while (x!=0){
rev = rev * 10 + x % 10;
x = x / 10;
}
if (rev > INT_MAX || rev < INT_MIN)
return 0;
return (int)rev;
}

int reverse(int x) {
int ans = 0;
while (x) {
int temp = ans * 10 + x % 10;
if (temp / 10 != ans)    //检查溢出
return 0;
ans = temp;
x /= 10;
}
return ans;
}

GitHub-Leetcode:https://github.com/wenwu313/LeetCode