7. Reverse Integer

题目

我的代码

class Solution(object):
    def reverse(self, x):
        """
        :type x: int
        :rtype: int
        """
        sign=False
        if x<0:
            sign =True
            x=-x
        li=[]
        while x>0:
            li.append(x%10)
            x/=10
        base=1
        result=0
        for i in range(len(li)-1,-1,-1):
            result+=base*li[i]
            base*=10
        if result>2**31-1:
            return 0
        if sign:
            return -result
        else:
            return result

优秀代码

class Solution(object):
    def reverse(self, x):
        """
        :type x: int
        :rtype: int
        """
        int_max = 2**31
        reverse = 0
        flag = 0
        if x<0 :
            x = abs(x)
            flag = 1
        while x != 0:    
            digit = x%10
            reverse = reverse*10 + digit
            x = x // 10
        if (reverse > int_max):
            return 0
        if flag == 1:
            reverse = reverse*(-1)
        return reverse