Question

Exercise 1. (Sum of Integers) Implement the functions sum_iter() and sum_rec() in sum_of_ints.py that take an integer n as argument and return the sum S(n) = 1 + 2 + 3 + · · · + n, computed iteratively (using a loop) and recursively. The recurrence equation for the latter implementation is

Answer 1

Step-by-step explanation:

We'll start out by prompting users to input an integer n. Then we create 2 functions to calculate the total, one by iteration and the other by recursion.

n = input('Please input an integer n')

def sum_iter(n):

total = 0

for i in range(n+1):

total += i

return total

sum_iter(n)

def sum_rec(n):

if n == 0:

return 0

else:

return n + sum_rec(n-1)

sum_rec(n)