#! /usr/bin/python
# coding=utf-8
import math
def main(x,y):
#对减数取反
x, y = bin(x)[2:], bin(y)[2:]
l = max([len(x),len(y)]) #最大长度
#对y取反
y = "1" * (l - len(y)) + "".join(['1' if i == '0' else '0' for i in y])
x,y = int(x,2), int(y,2)
z = x + y + 1
z = bin(z)
#拿掉最高位
z = z[3:]
return int(z,2)
if __name__ == '__main__':
import unittest,random
class cacheTest(unittest.TestCase):
def test_img(self):
for i in range(0,100000):
x, y = random.randint(1, 1000),random.randint(1, 1000)
if x < y : x,y = y,x
self.assertEqual(main(x, y), x - y)
unittest.main()
