Lecture "Brute-force algorithms", exercise 4

[essepuntato]

Write in Python the function def my_range(stop_number) which behave like the built-in function range() introduced in Section "Insertion sort" and returns a proper list, and accompany the function with the related test case. It is not possible to use the built-in function range() in the implementation.

[edoardodalborgo]

def test_my_range(stop_number):
    counts = 0
    for a in my_range(stop_number):
        counts += 1
    if counts == stop_number:
        return True
    else: return False

def my_range(stop_number):
    my_range_list = []
    i = 0
    while i < stop_number:
        my_range_list.append(i)
        i += 1
    return my_range_list

x = int(input("Enter the range that you would obtain: "))
print(test_my_range(x))

[diegochillo]

def my_range(stop_number):
   my_range=list()
   n=0
   while (n<stop_number):
    my_range.insert(n,n)
    n=n+1

   return my_range

def test_my_range(stop_number, expected):
   result=my_range(stop_number)
   return result==expected

print(test_my_range(5, [0,1,2,3,4]))

[gabrielefiorenza]

def test_my_range(stop_number,expected):
    result = my_range(stop_number)
    if result == expected:
        return True
    else:
        return False

def my_range(stop_number):
    result = []
    number = 0
    result.append(number)
    while number != (stop_number -1):
        number += 1
        result.append(number)
    return result

print (test_my_range(4,[0,1,2,3]))
print (test_my_range(3,[0,1]))

[dbrembilla]

def test_my_range(stop_number, expected):
    result=my_range(stop_number)
    return result ==expected

def my_range(stop_number):
    x = 0
    my_range_list = list()
    while x < stop_number:
        my_range_list.append(x)
        x += 1
    return my_range_list

print(test_my_range(4, [0 , 1, 2, 3]))

[ChiaraCati]

# Test
def test_my_range(stop_number, expected):
    result = my_range(stop_number)
    if result == expected:
        return True
    else:
        return False

# Function    
def my_range(stop_number):
    my_list = []
    c=0
    while c < stop_number:
        my_list.append(c)
        c+=1
    return my_list

#print(my_range(6))

print(test_my_range(6, ([0, 1, 2, 3, 4, 5]))) # Output : True
print(test_my_range(4, ([1, 2, 3, 4])))  # Output : False
print(test_my_range(0, ([0]))) # Output : False
print(test_my_range(0, ([]))) # Output : True

me and Giorgia Sampò did it together

👭

[fcagnola]

# Write in Python the function def my_range(stop_number) which behaves like the
# built-in function range() introduced in Section "Insertion sort" and returns
# a proper list, and accompany the function with the related test case. It is
# not possible to use the built-in function range() in the implementation.

def test(stop_number, expected):
    result = my_range(stop_number)
    if result == expected:
        return True
    else:
        return False

def my_range(stop_number):
    result_list = [] # creates the final result, as a list object
    number = 0 # sets the starting point at 0
    while number != stop_number: # loops through integers between 0 and stop_number
        result_list.append(number) # adds each loop value to the final list
        number += 1
    return result_list #returns the result

print(test(5, [0, 1, 2, 3, 4])) # returns True
print(test(19, [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18])) # returns True

[AleRosae]

def test_my_range (stop_number, expected):
    result = my_range(stop_number)
    if result == expected:
        return True
    else:
        return False

def my_range(stop_number):
    n = 0
    my_list = list ()
    while n != stop_number:
        my_list.append(n)
        n=n + 1

    return my_list

print(test_my_range((4), [0, 1, 2, 3]))
print(test_my_range((10), [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
print(test_my_range((0), []))

[AlessandraFa]

def test_my_range(stop_number, expected):
    result = my_range(stop_number)
    if result == expected:
        return True
    else:
        return False

def my_range(stop_number):
    a = 0
    range_list = list()
    while a < stop_number:
        range_list.append(a)
        a += 1
    return range_list

print(test_my_range((8), [0, 1, 2, 3, 4, 5, 6, 7]))
print(test_my_range((1), [0]))

[yunglong28]

#This is the function that simulates range()

def my_range (stop_number):
    range = []
    n = 0
    while n < stop_number:
        range.append(n)
        n=n+1
    return range
print(my_range(8))

#This is the test function
def test_myrange (stop_number, expected):
    result = my_range(stop_number)
    if result == expected:
        return True
    else:
        return False
print(test_myrange(8, [0, 1, 2, 3, 4, 5, 6, 7]))

[SusannaPinotti]

def test_my_range(stop_number, expected):
    res = my_range(stop_number)
    if expected == res:
        return True
    else:
        return False

def my_range(stop_number):
    output_list = list()
    n = 0
    while n < stop_number:
        output_list.append (n)
        n += 1
    return output_list

print(test_my_range((6), [0,1,2,3,4,5])) #return True
print(test_my_range((0), [])) #returns True
print(test_my_range((0), [0])) #return False

[IlaRoss]

#test
def test_my_range(stop_number, range_list):
    result = my_range(stop_number)
    if result == range_list:
        return True
    else:
        return False

#algorithm
def my_range(stop_number):
    range_list = list()
    prov_list = list()
    prov_number = (stop_number-1)

    if stop_number == 0:
        return range_list

    elif stop_number < 0:
        return 'Error'

    else:

        while prov_number >= 0:
            prov_list.append(prov_number)
            prov_number -= 1

        for item in prov_list:
            range_list.insert(0, item)

        return range_list

#test runs
print(test_my_range(5, [0, 1, 2, 3, 4]))
print(test_my_range(0, []))
print(test_my_range(-3, 'Error'))

#algorithm execution
print(my_range(12))
print(my_range(0))
print(my_range(-15))

[LuisAmmi]

# test
def test_my_range(stop_number, expected):
    result = my_range(stop_number)
    if result == expected:
        return True
    else:
        return False

# code
def my_range(stop_number):
    output_list = list()
    n = 0                  # initialize n
    while n != stop_number:
        output_list.append(n)
        n += 1
    else:
        return output_list

print(test_my_range(3, [0, 1, 2]))
print(test_my_range(2, [0, 1]))
print(test_my_range(0, []))```

[vanessabonanno]

def test_my_range(stop_number, expected):
    result = my_range(stop_number)
    if expected == result:
        return True
    else:
        return False

def my_range(stop_number):
    my_list = []
    x = 0
    while x < stop_number:
        my_list.append(x)
        x += 1
    return my_list

print(test_my_range(4, [0, 1, 2, 3]))# output: True
print(test_my_range(2, [1, 2]))      # output: False (starting number will be 0,
                                     # not 1 because x=0; 2 is not included in list since
                                     # there is '<' and not 'less or equal to')
print(my_range(4))                   # [0, 1, 2, 3]

[AlessandroBertozzi]

def test_my_range(stop_number, expected):
    result = my_range(stop_number)
    if result == expected:
        return True
    return False

def my_range(stop_number):
    counter = 0
    list_number = []
    while counter < stop_number:
        list_number.append(counter)
        counter += 1
    return list_number

print(test_my_range(3, [0, 1, 2]))
print(test_my_range(7, [0, 1, 2, 3, 4, 5, 6]))
print(test_my_range(0, []))

[SarahTew]

def my_range(stop_number):
    if stop_number>=0:
        n=0
        range_result=list()
        while n<stop_number:
            range_result.append(n)
            n=n+1
        return(range_result)
    else:
        return("Negative Number!")

#print ranges    
print(my_range(5))
print(my_range(3))
print(my_range(-5))
print(my_range(0))
print(my_range(3.3))

#test my_range function
def test_my_range(stop_number, expected):
    result=my_range(stop_number)
    if result==expected:
        return True
    else:
        return False
print(test_my_range(3, [0, 1, 2]))
print(test_my_range(0, []))
print(test_my_range(-9, "Negative Number!"))

[essepuntato]

Hi all,

A general comment: can you try to run the range function in Python with the following input, to see what actually happens? Does your function work as the original one?

range(-4)

[SofiBar]

exercise 4:

`def test_my_range(stop_number, expected):
    if expected == my_range(stop_number):
        return True
    else:
        return False

def my_range(stop_number):
    count = 0
    output_list = []

    while count < stop_number:
        output_list.append(count)
        count += 1
    return output_list

print(test_my_range(5, [0, 1, 2, 3, 4]))
print(test_my_range(7, [0, 1, 2, 3, 4, 5, 6]))
print(test_my_range(4, [0, 1, 2, 3]))

Range issue: if I write a negative number my function returns an empty list because -4 is less than 0 so the condition is never true.