Lecture "Recursion", exercise 1

[essepuntato]

Define a recursive function def exponentiation(base_number, exponent) for implementing the exponentiation operation. Test (by implementing the related test case) it on the following inputs: 3⁴, 17¹, and 2⁰.

[11051620]

def exponentation(base_number, exponent):
if exponent == 0:
return 1
else:
return base_number * exponentation(base_number, exponent - 1)

[martasoricetti]

[ManueleVeggi]

def test_exponentiation(base_number, exponent,expected):
    result = exponentiation(base_number, exponent)
    if result == expected:
        return True
    else:
        return False
    
def exponentiation(base_number, exponent):
    if exponent == 0:
        return 1
    else:
        return base_number*exponentiation(base_number, exponent-1)
        
print(test_exponentiation(3, 4, 81))
print(test_exponentiation(17, 1, 17))
print(test_exponentiation(2, 0, 1))

The output is:

True
True
True

[Postitisnt]

def exponentiation(base_number, exponent):
    if exponent == 0:
        return 1
    else:
        return base_number * exponentiation (base_number, exponent -1)

def test_exp (base_number, exponent, expected):
    if expected == exponentiation (base_number, exponent):
        return True
    else:
        return False

test_1 = test_exp(3, 4, 81)
test_2 = test_exp(17, 1, 17)
test_3 = test_exp(2, 0, 1)
print(test_1)
print(test_2)
print(test_3)

[giorgimariachiara]

def test_exponentiation(base_number, exponent, expected):
    result = exponentiation(base_number, exponent)
    if result == expected:
        return True
    else:
        return False


def exponentiation(base_number, exponent):
    if exponent == 0:
        return 1
    else:
    
        return base_number * exponentiation(base_number, exponent - 1)

print(test_exponentiation(3, 4, 81))
print(test_exponentiation(17, 1, 17))
print(test_exponentiation(2, 0, 1))

[tommasobattisti]

def test_exp(base_number, exponent, expected):
    result = exponentiation(base_number, exponent)
    if result == expected:
        return True
    else:
        return False

def exponentiation(base_number, exponent):
    if exponent == 0:
        return 1
    else:
        return base_number * exponentiation(base_number, exponent -1)


print(test_exp(3, 4, 81))
print(test_exp(17, 1, 17))
print(test_exp(2, 0, 1))

[federicabonifazi]

def my_test(base_number, exponent, expected):
    result = exponentiation(base_number, exponent)
    if expected == result:
        return True
    else:
        return False

def exponentiation(base_number, exponent):
    if exponent == 0:
        return 1
    else:
        return base_number * exponentiation(base_number, exponent-1)

print (my_test(3, 4, 81))
print (my_test(17, 1, 17))
print (my_test(2, 0, 1))

[CarmenSantaniello]

def test_exponentiation(base_number, exponent, expected):
    result = exponentiation(base_number, exponent)
    if expected == result:
        return True
    else:
        return False

def exponentiation(base_number, exponent):
    if exponent == 0:
        return 1
    else:
        return base_number*exponentiation(base_number, exponent-1)

print(test_exponentiation(3, 4, 81))
print(test_exponentiation(17, 1, 17))
print(test_exponentiation(2, 0, 1))
print(exponentiation(3, 4))
print(exponentiation(17, 1))
print(exponentiation(2, 0))

It returns:

True
True
True
81
17
1

[OrsolaMBorrini]

def test_exponentation(base_number,exponent,expected):
    result = exponentation(base_number,exponent)
    if result == expected:
        return True
    else:
        return False

def exponentation(base_number,exponent):
    if exponent == 0:
        return 1
    else:
        return base_number*exponentation(base_number,exponent-1)

print(test_exponentation(3,4,81)) #It returns True
print(test_exponentation(17,1,17)) #It returns True
print(test_exponentation(2,0,1)) #It returns True

[AmeliaLamargese]

def test_exponentiation(base, exponent, expected):
    result = exponentiation(base, exponent)
    if result == expected:
        return True
    else:
        return False

def exponentiation(base, exponent):
    if exponent==0:
        return 1
    else:
        return base*exponentiation(base, exponent -1)

print(test_exponentiation(3, 4, 81))                   
print(test_exponentiation(17, 1, 17))
print(test_exponentiation(2, 0, 1))

[elizastuglik]

def test_exponentiation(base_number, exponent, expected):
    result = exponentiation(base_number, exponent)
    if result == expected:
        return True
    else:
        return False


def exponentiation(base_number, exponent):
    if exponent == 0:
        return 1
    else:
    
        return base_number * exponentiation(base_number, exponent - 1)

print(test_exponentiation(3, 4, 81))
print(test_exponentiation(17, 1, 17))
print(test_exponentiation(2, 0, 1))

[SaraVell1]

[RebeccaJillianBeattie]

[ghasempouri1984]

This function can return a proper result for negative integer exponents and also proper error message return, for non-integer exponents and also a special case of zero power zero and zero power negative exponent. This function rounds the result of a negative integer exponent with 4 digits.

# Test case for the function
def test_exponentation(base_number, exponent, expected):
    result = exponentation(base_number, exponent)
    if expected == result:
        return True
    else:
        return False


# Code of function
def exponentation(base_number, exponent):
    if base_number == 0:
        if exponent <= 0:
            return "undefined"
        else:
            return 0
    elif type(exponent) != int:
        return "this function can not calculate non-integer exponent"

    elif exponent == 0:
        return 1

    elif exponent < 0:

        return round(1/(base_number * exponentation(base_number, abs(exponent) - 1)), 4)

    else:
        return base_number * exponentation(base_number, exponent - 1)


# Tests
print(test_exponentation(0, 0, "indeterminate form"))
print(test_exponentation(0, -5, "indeterminate form"))
print(test_exponentation(2, 2.1, "this function can not calculate non-integer exponent"))
print(test_exponentation(0, 1.5, 0))
print(test_exponentation(2, 0, 1))
print(test_exponentation(0, 10, 0))
print(test_exponentation(3, 4, 81))
print(test_exponentation(17, 1, 17))
print(test_exponentation(-4, 0, 1))
print(test_exponentation(-2, -3, -0.125))
print(test_exponentation(-3.11, -2, 0.1034))