LeetCode-in-All

11. Container With Most Water

Medium

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 the line i is at (i, ai) and (i, 0). Find two lines, which, together with the x-axis forms a container, such that the container contains the most water.

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

Example 3:

Input: height = [4,3,2,1,4]

Output: 16

Example 4:

Input: height = [1,2,1]

Output: 2

Constraints:

Solution

class Solution {
    fun maxArea(height: IntArray): Int {
        var max = 0
        if (height.isNotEmpty()) {
            var left = 0
            var right = height.size - 1
            while (left < right) {
                // next two if conditions are to make sure there are two non-zero containers to
                // hold water. If not move next to find one
                if (height[left] == 0) {
                    left++
                    continue
                }
                if (height[right] == 0) {
                    right--
                    continue
                }
                // if control came here that means left and right containers are non zero and
                // can hold water. Get the count of containers and multiple by lower container
                if (height[left] < height[right]) {
                    max = Math.max(max, (right - left) * height[left])
                    left++
                } else {
                    max = Math.max(max, (right - left) * height[right])
                    right--
                }
            }
        }
        return max
    }
}