equilibiruim_point.py

# Given an array A your task is to tell at which position the equilibrium first occurs in the array. Equilibrium position in an array is a position such that the sum of elements below it is equal to the sum of elements after it.

# Input:
# The first line of input contains an integer T denoting the no of test cases then T test cases follow. First line of each test case contains an integer N denoting the size of the array. Then in the next line are N space separated values of the array A.

# Output:
# For each test case in a new  line print the position at which the elements are at equilibrium if no equilibrium point exists print -1.

# Constraints:
# 1<=T<=100
# 1<=N<=100

# Example:
# Input:
# 2
# 1
# 1
# 5
# 1 3 5 2 2

# Output:
# 1
# 3

# Explanation:
# 1. Since its the only element hence its the only equilibrium point
# 2. For second test case equilibrium point is at position 3 as elements below it (1+3) = elements after it (2+2)
 

def equilibrium_point(arr,n):
    
    total = 0
    for item in arr:
        total  = total + item
    
    left_sum = 0
    right_sum = total

    for i in range(0,n):
        right_sum = right_sum - arr[i]
        if left_sum == right_sum:
            print(i+1)
            return
        left_sum = left_sum + arr[i]
    print(-1)
    return

t = int(input())

for i in range(0,t):
    numbers = input().strip().split()
    n = int(numbers[0])

    arr = [int(x) for x in input().strip().split(" ")]
    equilibrium_point(arr,n)