equi2.py

import math

# quick test cases
A = [-7, 1, 5, 2, -4, 3, 0]
B = [1, 2, 3, 4, 3, 2, 1]
C = [99, 0, 66, 32, 1] 
D = [1, -1, 1, -1, 1, -1, 1]
E = [0,0,0]
F = [0,53,9]
G = [0,1,-1]
 
tests = [A,B,C,D,E,F,G]

def equi(A):
    l = 0 # left of current index
    r = 0 # right of current index
    s = [] # list of eq. indices

    for i in range(len(A)):
        # get abs values of sum of numbers on either side of current indices
        l = math.fabs(sum(A[:i]))        
        r = math.fabs(sum(A[i+1:]))        

        # add matches to list
        if (l == r):
            s.append(i)
    if s:    
        return s
    else:
        return -1  

if __name__ == "__main__":
    for i in tests:
        print  i, equi(i)