Problem Brief

Trapping Rain Water

INTERNOA

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.

1Example 1

Input

height = [0,1,0,2,1,0,1,3,2,1,2,1]

Output

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.

2Example 2

Input

height = [4,2,0,3,2,5]

Output

Explanation

No explanation provided.

Constraints

Limits and guarantees your solution can rely on.

n == height.length
1 <= n <= 2 * 10^4
0 <= height[i] <= 10^5

Draft autosaves locally

public int trap(int[] height) {
  // write your code here (You might want to also refert to LC42 :)
}

Input

height

[0,1,0,2,1,0,1,3,2,1,2,1]

Output