[LeetCode] 7. Reverse Integer (Java)

Description

Given a signed 32-bit integer x, return x with its digits reversed. If reversing x causes the value to go outside the signed 32-bit integer range [-231, 231 - 1], then return 0.

Assume the environment does not allow you to store 64-bit integers (signed or unsigned).

 

주어진 수의 앞 뒤 순서를 바꾼다.

 

Example 1:

Input: x = 123
Output: 321

Example 2:

Input: x = -123
Output: -321

Example 3:

Input: x = 120
Output: 21

 

Constraints:

• -231 <= x <= 231 - 1

Solution

class Solution {
    public int reverse(int x) {
        
        long answer = 0;
        while(x!=0){
            answer = answer*10+(x%10);
            x /= 10;
        }
        
        if (-Integer.MAX_VALUE <= answer && answer <= Integer.MAX_VALUE) {
            return (int)answer;
        } else {
            return 0;
        }
    }
}