11. Container With Most Water

문제

You are given an integer array height of length n. There are n vertical lines drawn such that the two endpoints of the ith line are (i, 0) and (i, height[i]).

Find two lines that together with the x-axis form a container, such that the container contains the most water.

Return the maximum amount of water a container can store.

Notice that you may not slant the container.

 

Example 1:

Input: height = [1,8,6,2,5,4,8,3,7]
Output: 49
Explanation: The above vertical lines are represented by array [1,8,6,2,5,4,8,3,7]. In this case, the max area of water (blue section) the container can contain is 49.

Example 2:

Input: height = [1,1]
Output: 1

 

Constraints:

• n == height.length
• 2 <= n <= 105
• 0 <= height[i] <= 104

 

https://leetcode.com/problems/container-with-most-water

 

풀이

while문을 사용하여 양쪽에서 물 양을 비교하며 최대값만 저장하게끔 진행했다.

어차피 양쪽의 높이 중 낮은 높이에 따라 양이 결정되니, 이중 for문을 이용하여 전부 다 비교하기 보다는 높은 쪽을 고정해 두고 낮은 쪽만 움직이게끔 하는 것이 낫다고 생각했다.

 

코드

class Solution {
    public int maxArea(int[] height) {
        int max = 0;
        int leftIdx = 0;
        int rightIdx = height.length - 1;
        
        while(leftIdx < rightIdx) {
        	int water = (rightIdx - leftIdx) * Math.min(height[leftIdx], height[rightIdx]);
        	max = Math.max(max, water);
        	if(height[leftIdx] < height[rightIdx]) {
        		leftIdx++;
        	} else {
        		rightIdx--;
        	}
        }
        
        return max;
    }
}

 

 

결과

Runtime : 5 ms

Memory Usage : 57.90 MB