LeetCode Container With Most Water (JavaScript)

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

문제 설명

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

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문제 풀이

투 포인터 알고리즘을 이용하여 해결

left : 왼쪽 끝, right : 오른쪽 끝

left, right에 해당하는 높이중 낮은 높이를 기준으로 넓이를 구함 -> answer 최신화 (큰 값으로)

left, right 중 작은 값을 이동 시킴 (이동 시킴으로 써 더 큰 높이를 만나기 위해)

/**
 * @param {number[]} height
 * @return {number}
 */
var maxArea = function(height) {
    let answer = 0;

    let [left, right] = [0, height.length - 1];

    while (left < right) {
        const h = Math.min(height[left], height[right]);
        const r = right - left;
        answer = Math.max(answer, h * r);

        if (height[left] < height[right]) {
            left++;
        } else {
            right--;
        }
    }

    return answer;
};

 

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결론

투 포인터 알고리즘을 통해 구현

포인터를 이동시키는 로직이 핵심