#
# A program that shows that list members value might be changed 
# in a function + testing
#
# function 'square' squares all the elements of the list x
#

def square(x):
    n=len(x)
    for i in range(n):
        x[i]=x[i]*x[i]

def test1():
    print("TEST1")
    x = [1,2,3,4,5]
    print("the input list: ",x)
    y = x.copy()
    square(y)
    print("the list after 'square' call: ",y)
    for i in range(len(x)):
        if y[i] == x[i]**2:
            print("\t passed")
        else:
            print("\t failed on i = ",i)

def test2():
    print("TEST2")
    x=[0,0,0]
    print("the input list: ",x)
    square(x)
    print("the list after 'square' call:",x)
    for item in x:
        if item == 0:
            print("\t passed")
        else:
            print("\t failed on i = ",i)

def test3():
    print("TEST3")
    x = [-1,-2,-3]
    print("the input list: ",x)
    y = x.copy()
    square(y)
    print("the list after 'square' call:",y)
    for i in range(3):
        if y[i] == x[i]**2:
            print("\t passed")
        else:
            print("\t failed on i = ",i)

test1()
test2()
test3()