let jump = 0

         let curr = 0 

         let res = 0

         for(let i=0; i<n-1; i++){

              res=Math.max(res,arr[i]+i);

              if(curr==i){

                 curr=res;

                jump++;

             }

        }

        if(curr>=(n-1)){

          return jump;

        } else {

           return -1;

        }

class Solution868

{

    //Function to find minimum number of jumps to reach the end of the array.

    public static int minimumJumps(int arr[], int n)

    {

        // your code here

​

        int jumps = 0;

        int curr = 0;

        int max = 0;

​

        for(int i=0;i<n-1;i++)

        {

            max = Math.max(max, i+arr[i]);

​

            if(curr == i)

            {

                jumps++;

                curr = max;

            }

        }

​

        return curr >= n-1 ? jumps: -1;

    }

}