11.container-with-most-water.cpp

/*
 * @lc app=leetcode id=11 lang=cpp
 *
 * [11] Container With Most Water
 *
 * https://leetcode.com/problems/container-with-most-water/description/
 *
 * algorithms
 * Medium (50.01%)
 * Likes:    5996
 * Dislikes: 579
 * Total Accepted:    648.6K
 * Total Submissions: 1.3M
 * Testcase Example:  '[1,8,6,2,5,4,8,3,7]'
 *
 * 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 and n is at least 2.
 *
 *
 *
 *
 *
 * 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:
 *
 *
 * Input: [1,8,6,2,5,4,8,3,7]
 * Output: 49
 */
#include <vector>
using namespace std;
// @lc code=start
class Solution {
   public:
    int maxArea(vector<int>& height) {
        int l = 0, r = height.size() - 1;
        int maxA = 0;
        while (l < r) {
            int w = r - l;
            int h;
            if (height[l] < height[r]) {
                h = height[l++];
            } else {
                h = height[r--];
            }

            int a = w * h;
            if (a > maxA) {
                maxA = a;
            }
        }

        return maxA;
    }
};
// @lc code=end