Problem

Given an array of integers, find the sum of its elements.
Example input: [1, 2, 3, 4, 5]
Example output: 15

Solution

# Solution:

def sum_array(array):
  sum = 0
  for i in array:
    sum += i
  return sum

# Explanation:

# This solution is optimal because it is O(n) time complexity.
# It is O(n) because it iterates through the array once.
# It is not O(n^2) because it does not iterate through the array twice.
# It is not O(n^3) because it does not iterate through the array three times.
# It is not O(log n) because it does not divide the array in half.
# It is not O(1) because it does not return a constant value.