// Function to return minimum number of jumps to end of array

class Solution{

  public:

    int minJumps(int arr[], int n){

        if(arr[0] == 0 && n>1) return -1;

        if(n == 1) return 0;

        int steps = arr[0];

        int maxReach = arr[0];

        int jumps = 1;

          for(int i = 1; i<n; i++){

            if(i == n-1) return jumps;

            // Ab apan agle point par aagye to maxReach nikalo aur store kralo

            if(steps) {

             maxReach = max(maxReach, arr[i]+i);

             // Ab apan agle point pr aagye hai to ek step kam kardo

             steps--;

            }

            // check kro ki steps khatm to nhi ho gye

            if(steps == 0){

                // agar end point tak pahuchne se pahale koi zero mil gya aur usse pahale koi maxReach nhi tha

                if(i>=maxReach) return -1;

                // steps khatm hue matlab new point par aagye

                // yha se bhi jump lga do

                // apan jump tabhi lagayenge jab steps khatm ho jayenge

                jumps++;

                // steps ko update krlo

                steps = maxReach - i;

            }

        }

        return -1;

    }

};