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
class Solution {
public:
int reverse(int x) {
int flag = 1;
if(x < 0){
flag = -1;
x = -x;
}
long long sum = 0; //用long来得到结果
while(x){
sum = (sum * 10 + (x % 10));
x /= 10;
}
sum = sum * flag;
return (sum > INT_MAX || sum < INT_MIN)? 0 : sum;
}
};