【LeetCode】Reverse Integer

Reverse Integer

Total Accepted: 6363 Total Submissions: 15698 My Submissions

Reverse digits of an integer.

Example1: x = 123, return 321

Example2: x = -123, return -321

恩，习惯上，用/求除数，用%求余数。

我比较擅长用字符串。

Java AC

方法1

public class Solution {
    public int reverse(int x) {
        int flag = x > 0 ? 1 : -1;
        int num = Math.abs(x);
        int result = 0;
        while(num > 0){
            result = result * 10 + num % 10;
            num /= 10;
        }
        return result * flag;
    }
}

方法2

public class Solution {
    public int reverse(int x) {
        int flag = x > 0 ? 1 : -1;
        int num = Math.abs(x);
        String numStr = num + "";
        int len = numStr.length();
        StringBuffer sb = new StringBuffer();
        for(int i = len-1; i >= 0; i--){
            sb.append(numStr.charAt(i));
        }
        int result = Integer.parseInt(sb.toString());
        return result * flag;
    }
}