Container With Most Water


#1

Given n non-negative integers a1, a2, ..., a, 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

#2

Assuming the widest container part could hold more water, we could start from the start and end of the heights. The maximum water you can hold between two heights is usually the product of distance between them and smaller height of the two.

Based on this logic, below code in Golang beats 100% of the LC.

func maxArea(height []int) int {
    i, j := 0, len(height)-1
    volume := 0
    for i < j {
        volume = maxInt(volume, (j-i) * minInt(height[i], height[j]))
        if height[i] > height[j]{
            j--
        } else {
            i++
        }      
    }
    return volume
}

func maxInt(a, b int) int {
    if a<b{
        return b
    }
    return a
}

func minInt(a, b int) int {
    if a<b{
        return a
    }
    return b
}