LeetCode提交编译错误提示求解答

[xyh1re]

LeetCode第七题Reverse Integer,用比较笨的办法做，代码如下：

public class Solution {
    public int reverse(int x) {
        int re = 0;
		if (x < 0) {
			re = 0 - x;
		} else {
			re = x;
		}
		String s = String.valueOf(re);
		int length = s.length();
		int n = s.length() / 2;
		char[] ch = s.toCharArray();
		for (int i = 0; i < n; i++) {
			char c = ch[i];
			ch[i] = ch[length - 1 - i];
			ch[length - 1 - i] = c;
		}
		s = new String(ch);
		long a = 0L;
		a = Long.parseLong(s);
		if (x > 0 && a > Integer.MAX_VALUE) {
			return 0;
		}
		if (x < 0 && a < (0 - Integer.MIN_VALUE)) {
			return 0;
		}
		if (x > 0) {
			return Integer.parseInt(s);
		} else {
			return 0 - Integer.parseInt(s);
		}
    }
}

提交时错误：
Runtime Error Message: Line 20: java.lang.NumberFormatException: For input string: "8463847412-"
Last executed input: -2147483648
也就是a = Long.parseLong(s);这行代码的错误，按理说程序运行到这一步是不会出现不能转化为long类型的字符串s的情况，不明白该怎么改，请大家多多指教！谢谢！

[xyh1re]

明白了，如果输入是-2^31的话，第五行re的值就会溢出