7. Reverse Integer

Reverse digits of an integer.
Example1: x = 123, return 321Example2: x = -123, return -321
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**Note:
**The input is assumed to be a 32-bit signed integer. Your function should return 0 when the reversed integer overflows.
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Python

• 最简单翻转数字的方法 int(str(x)[::-1]
• 注意这里如果超出范围[-2^31, 2^31]要置为0
• 2^31 = 2147483648

class Solution(object):
    def reverse(self, x):
        """
        :type x: int
        :rtype: int
        """
        result = int(str(x)[::-1]) if x >= 0 else -1 * int(str(-x)[::-1])
        return result if result < 2147483648 and result > -2147483648 else 0