Find Reachibility

 Find Reachibility -- Juspay Hiring Solutions

import java.util.*;

import java.lang.*;
import java.io.*;

class Codechef
{
	public static void main (String[] args){
		Scanner sc = new Scanner(System.in); 
        int t = sc.nextInt();

while(t!=0){
    
    int n = sc.nextInt();
    int sum = 0, diff = 0;
    int[] A = new int[n];
    int[]B = new int[n];

    for (int i = 1; i < n; i++){
        A[i] = sc.nextInt();
        sum += A[i];
        B[i] = A[i];
        A[i] = sum;
    }
    for (int i = 0; i < n-1; i++){
        diff = A[i+1] - B[i];
        if(diff > 0){ 
            B[i+1] = B[i] + diff + B[i+1];
        }
        else{
            B[i+1] = B[i] + B[i+1];
        }
    }
    System.out.println(B[n-1]);
    t--;
    
     }
 
  }
}