jump gaime 2

public class Solution {
    public int jump(int[] A) {
        if(A==null || A.length==0) 
        return 0; 
        int lastReach = 0; 
        int reach = 0; 
        int step = 0; 
        for(int i=0;i<=reach&&i<A.length;i++) 
        { 
            if(i>lastReach) 
            { 
                step++; 
                lastReach = reach; 
            } 
            reach = Math.max(reach,A[i]+i); 
        } 
        if(reach<A.length-1) 
            return 0; 
        return step;

    }
}