Examples

Python examples

# https://www.dropbox.com/s/xpfbcnnnkmjvwdv/Screenshot%202015-02-02%2022.02.06.png?dl=0
# Equilibrium problem

array = [-1, 3, -4, 5, 1, -6, 2, 1]

def solution(array):
	right = sum(array)
	left = 0
	before = 0
	for index, val in enumerate(array):
		left = left + before
		right = right - val
		if left == right:
			return index
		before = val
	return -1

print solution(array)