checking integer overflow in python

Question

class Solution(object):
    def reverse(self, x):
        \"\"\"
        :type x: int
        :rtype: int
        \"\"\"
        negative = False
        if(x < 0):
          


        

Answer 1

The largest 32-bit signed integer is (1 << 31) - 1 which is (2**31)-1 but not (2**32).

Try This way :

class Solution(object):
  def reverse(self, x):
    """
    :type x: int
    :rtype: int
    """
    negative = False
    if (x < 0):
      x = x * -1
      negative = True
    else:
      x = x
    sum = 0
    dig = 1
    strX = str(x)
    lst = list(strX)
    for i in lst:
      sum += int(i) * dig
      dig *= 10

    if (abs(sum) > ((1 << 31) - 1)): #use (1 << 31) - 1) instead of 2 ** 32
      return 0
    elif (negative == True):
      return sum * -1
    else:
      return sum

if __name__ == '__main__':
    x = 1563847412
    sol = Solution().reverse(x)
    print(sol)

Output :

0