Equilibrium Point.cpp

#include <iostream>
using namespace std;


// } Driver Code Ends
class Solution{
    public:
    // Function to find equilibrium point in the array.
    // a: input array
    // n: size of array
    int equilibriumPoint(long long a[], int n) {
    
        // Your code here
         if(n==1)
        return 1;
    int sum =0;
    for(int i =0; i <n; i++)
        sum += a[i];
    
    int l_sum =0;
    for(int i =0; i < n; i++)
    {
        sum -= a[i];
        if(sum == l_sum)
            return i+1; 
        l_sum += a[i];
    }
    return -1;
    }

};

//{ Driver Code Starts.


int main() {

    long long t;
    
    //taking testcases
    cin >> t;

    while (t--) {
        long long n;
        
        //taking input n
        cin >> n;
        long long a[n];

        //adding elements to the array
        for (long long i = 0; i < n; i++) {
            cin >> a[i];
        }
        
        Solution ob;

        //calling equilibriumPoint() function
        cout << ob.equilibriumPoint(a, n) << endl;
    }
    return 0;
}