/*
 * 42. Trapping Rain Water
 * Difficulty: Hard
 * https://leetcode.com/problems/trapping-rain-water/
 * 
 * ──────────────────────────────────────────────────
 * 
 * Given n non-negative integers representing an elevation map where the
 * width of each bar is 1, compute how much water it can trap after
 * raining.
 * 
 *  
 * 
 * Example 1:
 * 
 * Input: height = [0,1,0,2,1,0,1,3,2,1,2,1]
 * Output: 6
 * Explanation: The above elevation map (black section) is represented
 * by array [0,1,0,2,1,0,1,3,2,1,2,1]. In this case, 6 units of rain
 * water (blue section) are being trapped.
 * 
 * Example 2:
 * 
 * Input: height = [4,2,0,3,2,5]
 * Output: 9
 * 
 *  
 * 
 * Constraints:
 * 
 * 	• n == height.length
 * 
 * 	• 1 <= n <= 2 * 10^4
 * 
 * 	• 0 <= height[i] <= 10^5
*/

/**
 * @param {number[]} height
 * @return {number}
 */
var trap = function(height) {
    
};