7. Reverse Integer

 

 

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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 hold integers within the 32-bit signed integer range. For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.

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