ContainerwithMostWaterlinearTC.java

import java.util.ArrayList;

public class ContainerwithMostWaterlinearTC {
    // 2 pointer approch
    public static int storeWater(ArrayList<Integer> height){
       int maxWater = 0;
       int lp = 0;
       int rp = height.size()-1;
       while(lp < rp){
        //calculate water area 
        int ht = Math.min(height.get(lp), height.get(rp));
        int width = rp - lp;
        int currWater = ht * width;
        maxWater = Math.max(maxWater, currWater);
        //update pointer
        if(height.get(lp) < height.get(rp)){
            lp++;
        }
        else{
            rp--;
        }

       }
       return maxWater;
    }

    
    public static void main(String[] args) {
         ArrayList<Integer> height = new ArrayList<>();
        height.add(1);
        height.add(8);
        height.add(6);
        height.add(2);
        height.add(5);
        height.add(4);
        height.add(8);
        height.add(3);
        height.add(7);
        System.out.println(storeWater(height));
    }
}