Question

This is the question

Write a function add(vals1, vals2) that takes as inputs two lists of 0 or more numbers, vals1 and vals2, and that uses recursion to construct and return a new list in which each element is the sum of the corresponding elements of vals1 and vals2. You may assume that the two lists have the same length.

For example:

>>> add([1, 2, 3], [3, 5, 8])
result: [4, 7, 11]

Note that:

• The first element of the result is the sum of the first elements of the original lists (1 + 3 –> 4).
• The second element of the result is the sum of the second elements of the original lists (2 + 5 –> 7).
• The third element of the result is the sum of the third elements of the original lists (3 + 8 –> 11)

And this is why i have for the code. But i have not learned del function and im afraid i cant use it.

im only allowed to use

• arithmetic operators: +, -, *, **, /, //, %
• boolean operators: <, >, <=, >=, ==, !=
• comments and docstrings
• conditional statements: if, elif, else
• len()
• logical operators: and, or, not
• list operations: indexing, slicing, skip-slicing, concatenation, construction
• print()
• recursion
• string operations: indexing, slicing, concatenation, duplication
• type()

def add(vals1,vals2):
    """return a new list in which each elements is the sum of
        the corresponding elements of val1 and vals2
        input: lists of 0 or more numbers
    """
    if (len(vals1))==0:
        return []
    else:
        x = vals1[0]+vals2[0]
        del vals1[0],vals2[0]
      
      

        return [x]+add(vals1,vals2)

Answer 1

The function is as follows:

# Definition of the function.

def add(vals1, vals2):

    # check the condition

    if(len(vals1)==0):

        # return empty array.

        return []

    else:

        # calculate the value.

        x = vals1[0]+ vals2[0];

   # return the value recursively.

    return [x] + add(vals1[1:], vals2[1:])

The complete executable code is as follows:

Program screenshots:

Sample Output:

Code to Copy:

# kindly use python 3.6

# kindly indent the code as given in above screenshot.

# Definition of the function.

def add(vals1, vals2):

    # check the condition

    if(len(vals1)==0):

        # return empty array.

        return []

    else:

        # calculate the value.

        x = vals1[0]+ vals2[0];

   # return the value recursively.

    return [x] + add(vals1[1:], vals2[1:])

# call the function.

print(add([1, 2, 3], [3, 5, 8]))