42. Trapping Rain Water
Hard
26.5K
366

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 * 104
  • 0 <= height[i] <= 105
Accepted
1.5M
Submissions
2.6M
Acceptance Rate
59.4%

Seen this question in a real interview before?
1/4
Yes
No

Discussion (0)

Related Topics
Copyright ©️ 2023 LeetCode All rights reserved