Stone Wall lesson 5 codility

import java.util.Stack;
class Solution {
    public int solution(int[] H) {
        // write your code in Java SE 8
        Stack<Integer> wall=new Stack<Integer>();
        int blocks=0;
        for(int index=0;index<H.length;index++){ 
            while(!wall.empty()&&H[index]<wall.peek()){ 
                 wall.pop();
                if(!wall.empty()&&H[index]>wall.peek()){ 
             wall.push(H[index]);
             blocks++;   
                }
            }            
            if(wall.empty()){
             wall.push(H[index]);
             blocks++;
            } 
            if(!wall.empty()&&H[index]>wall.peek()){
             wall.push(H[index]);
             blocks++;
            }          
        }
        return blocks;
    }
}