Container With Most Water

Problem Description

Given n non-negative integers a1, a2, ..., an, where each represents a point at coordinate (i, ai). n vertical lines are drawn such that the two endpoints of line i is at (i, ai) and (i, 0). Find two lines, which together with x-axis forms a container, such that the container contains the most water.

Note: You may not slant the container.

Solution
In this problem, we use 2 pointers, one runs from the 0, one runs backward.

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1. public class Solution {  
2.     public int maxArea(int[] height) {  
3.         //we assume the array height.length > 0  
4.         int max = 0;  
5.         int area;  
6.         for(int i=0, j=height.length-1; i<j;){  
7.               
8.             if(height[i] > height[j]){  
9.                 area = (j-i) * height[j];  
10.                 j--;  
11.             }else {  
12.                 area = (j-i) * height[i];  
13.                 i++;  
14.             }  
15.             if(area > max) max = area;  
16.         }  
17.         return max;  
18.     }  
19. }  

public class Solution {
    public int maxArea(int[] height) {
        //we assume the array height.length > 0
        int max = 0;
        int area;
        for(int i=0, j=height.length-1; i<j;){
            
            if(height[i] > height[j]){
                area = (j-i) * height[j];
                j--;
            }else {
                area = (j-i) * height[i];
                i++;
            }
            if(area > max) max = area;
        }
        return max;
    }
}