不使用第三方变量 交换两个数

# Original value
a = 5
b = 4
print("a = %d, b = %d" %(a, b))

# Way-01
c = a
a = b
b = c
print("a = %d, b = %d" %(a, b))

# Way-02
a = b - a
b = b - a
a = b + a
print("a = %d, b = %d" %(a, b))

# Way-03
a = a ^ b
b = a ^ b
a = a ^ b
print("a = %d, b = %d" %(a, b))

# Example output:
# a = 5, b = 4
# a = 4, b = 5
# a = 5, b = 4
# a = 4, b = 5

# Python customized
a, b = b, a
print("a = %d, b = %d" %(a, b))
# now output
# a = 5, b = 4