Description
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.
Examples
Input:
height = [0,1,0,2,1,0,1,3,2,1,2,1]Output:
6Explanation:
The elevation map traps 6 units of rain water.
Input:
height = [4,2,0,3,2,5]Output:
9Explanation:
9 units of water are trapped.
Input:
height = [1,2,3,4,5]Output:
0Explanation:
Edge case returning zero.
Constraints
- •
n == height.length - •
1 ≤ n ≤ 2 × 10⁴ - •
0 ≤ height[i] ≤ 10⁵