Equilibrium point
Submissions: 82825   Accuracy:

37.39%

  Difficulty: Easy   Marks: 2

Given an array A of N positive numbers. The task is to find the position where equilibrium first occurs in the array. Equilibrium position in an array is a position such that the sum of elements before it is equal to the sum of elements after it.

Input:
The first line of input contains an integer T, denoting the number 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 <= 106

1 <= Ai <= 108

Example:
Input:

2
1
1
5
1 3 5 2 2

Output:
1
3

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

 

** For More Input/Output Examples Use 'Expected Output' option **

Author: Ayush Saluja


If you have purchased any course from GeeksforGeeks then please ask your doubt on course discussion forum. You will get quick replies from GFG Moderators there.



Need help with your code? Please use ide.geeksforgeeks.org, generate link and share the link here.

to report an issue on this page.