Balanced sum X45803
Design the function suma_equilibrada(f) that, given a list of integers f, returns the smallest index i such that the sum of the elements of f from the first position until the position i is equal to the sum of the subsequent elements. Note that i has to be a valid position in the list. If this position does not exist, the function will return -1.
Sample session
>>> suma_equilibrada([1, 1, 1, 1]) 1 >>> suma_equilibrada([10, 10, 7, 3, 30]) 3 >>> suma_equilibrada([10, 20]) -1 >>> suma_equilibrada([-3, 5, -2]) 2 >>> suma_equilibrada([0]) 0 >>> suma_equilibrada([]) -1