List Equilibrium Index

list_equlibrium.py

__author__ = 'arefaey'


def list_equilibrium(l):
    s = sum(l)
    right_sum = s
    left_sum = 0
    for i in range(len(l)):
        elem = l[i]
        right_sum = right_sum - elem
        if right_sum == left_sum:
            print "The Equilibrium Index is: ", i, "for list: ", l
            return i
        left_sum = left_sum + elem
    print "There is no Equilibrium Index for list: ", l
    return None


l0 = []
l1 = [1]
l2 = [1, 2]
l3 = [1, 2, 1]
l4 = [1, 2, 1, -3, -4, 3, 5, 22, 1, 7, -2, -1]
test_lists = [l0, l1, l2, l3, l4]
for l in test_lists:
    list_equilibrium(l)