1637-widest-vertical-area-between-two-points-containing-no-points.rb

# frozen_string_literal: true

# 1637. Widest Vertical Area Between Two Points Containing No Points
# Medium
# https://leetcode.com/problems/widest-vertical-area-between-two-points-containing-no-points

=begin
Given n points on a 2D plane where points[i] = [xi, yi], Return the widest vertical area between two points such that no points are inside the area.
A vertical area is an area of fixed-width extending infinitely along the y-axis (i.e., infinite height). The widest vertical area is the one with the maximum width.
Note that points on the edge of a vertical area are not considered included in the area.

Example 1:
Input: points = [[8,7],[9,9],[7,4],[9,7]]
Output: 1
Explanation: Both the red and the blue area are optimal.

Example 2:
Input: points = [[3,1],[9,0],[1,0],[1,4],[5,3],[8,8]]
Output: 3

Constraints:
n == points.length
2 <= n <= 105
points[i].length == 2
0 <= xi, yi <= 109
=end

# @param {Integer[][]} points
# @return {Integer}
def max_width_of_vertical_area(points)
  points.sort! { |a, b| a[0] - b[0] }

  max_width = 0

  (1...points.length).each do |i|
    width = points[i][0] - points[i - 1][0]
    max_width = [max_width, width].max
  end

  max_width
end

# **************** #
#       TEST       #
# **************** #

require "test/unit"
class Test_max_width_of_vertical_area < Test::Unit::TestCase
  def test_
    assert_equal 1, max_width_of_vertical_area([[8, 7], [9, 9], [7, 4], [9, 7]])
    assert_equal 3, max_width_of_vertical_area([[3, 1], [9, 0], [1, 0], [1, 4], [5, 3], [8, 8]])
  end
end