# a=5,b=4,交换a和b的值
# 方法1
a = 5
b = 4
a, b = b, a
print(a)
print(b)
# 方法2,用中间变量c
a = 5
b = 4
c = a
a = b
b = c
print(a)
print(b)
# 方法3
a = 5
b = 4
a = a + b
b = a - b
a = a - b
print(a)
print(b)
# a=5,b=4,交换a和b的值
# 方法1
a = 5
b = 4
a, b = b, a
print(a)
print(b)
# 方法2,用中间变量c
a = 5
b = 4
c = a
a = b
b = c
print(a)
print(b)
# 方法3
a = 5
b = 4
a = a + b
b = a - b
a = a - b
print(a)
print(b)