Reverse digits of an integer.
Example1: x = 123, return 321
Example2: x = -123, return -321
Note:
The input is assumed to be a 32-bit signed integer. Your function should return 0 when the reversed integer overflows.
將一個整數(shù)中的數(shù)字進行顛倒，當顛倒后的整數(shù)溢出時，返回 0 (標記為 32 位整數(shù))。

分析

通過取余得到最后一位，循環(huán)，對于溢出進行判斷即可

代碼

public int reverse(int x) {
        int result = 0;

        while(x != 0) {
            int tail = x % 10;
            int newResult = result * 10 + tail;
            if((newResult-tail)/10 != result)
                return 0;
            result = newResult;
            x = x/10;
        }
        return result;
    }

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