python3

javascript

java

Rain Water Harvesting

Given `n` non-negative integers representing an elevation map where the width of each bar is `1`, compute how *much water it can harvest after raining* .

### Input Format:
First Parameter - `n` , size of the array   
Second Parameter - List of positive integer , `height`

### Output Format:
Return the number

### Example 1:
![img](https://devsnest-custom-images.s3.ap-south-1.amazonaws.com/rainwater%20harvesting)

    Input:
        n = 12
        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 harvested.

### Example 2:
    Input:
        n = 6
        height = [4 2 0 3 2 5]
    Output:
        9

#### Constraints:
+ n == height.length
+ 1 <= n <= 2 * 10^4^ 
+ 0 <= height[i] <=10^5^
+ Expected Time Complexity: O(n)
+ Expected Space Complexity: O(n)

function solve(n, height){
// CODE HERE
}

int solve(int n, vector<int> height){
//CODE HERE 
}

static int solve(int n, int[] height){
//CODE HERE 
}