Array Equilibrium Index

Level EASY

Find and return the equilibrium index of an array. Equilibrium index of an array is an index i such that the sum of elements at indices less than i is equal to the sum of elements at indices greater than i.

Element at index i is not included in either part.

If more than one equilibrium index is present, you need to return the first one. And return -1 if no equilibrium index is present.

Input format :

Line 1 : Size of input array
Line 2 : Array elements (separated by space)

Constraints:

Time Limit: 1 second
Size of input array lies in the range: [1, 1000000]

Sample Input :

7
-7 1 5 2 -4 3 0

Sample Output :

3 

	def equilibrium(arr):
	total_sum = sum(arr)
	leftsum = 0
	for i, num in enumerate(arr):
	total_sum -= num
	if leftsum == total_sum:
	return i
	leftsum += num
	return -1
	n=int(input())
	arr = list(map(int,input().split()))
	print(equilibrium(arr))

view raw Array Equilibrium Index.py hosted with ❤ by GitHub