Full Stack Engineer

You have been given a long type array/list 'arr’ of size 'n’.

It represents an elevation map wherein 'arr[i]’ denotes the elevation of the 'ith' bar.

Print the total amount of rainwater that can be trapped in these elevations.

Note :

The width of each bar is the same and is equal to 1.

Example:

Input: ‘n’ = 6, ‘arr’ = [3, 0, 0, 2, 0, 4].

Output: 10

Explanation: Refer to the image for better comprehension:

Note :

You don't need to print anything. It has already been taken care of. Just implement the given function.

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You are given an array of distinct elements, and you have to rearrange the array elements in a zig-zag fashion. In other words, for every odd position ‘i’ in the array 'ARR,' 'ARR'[i] should be greater than 'ARR'[i-1] and 'ARR'[i] should be greater than 'ARR'[i+1].

For example:

Given ‘N’ = 4, 
'ARR' = { 4, 3, 2, 1} 
Then a possible array is 3, 4, 1, 2.

Note:

You are supposed to return the array, which is in a zig-zag fashion.

Since there can be multiple answers for a particular array, any of the possible solutions are accepted.

It can be proved. A zig-zag array is always possible for a given array.

We have two water jugs: one with a capacity of 4 liters and the other with a capacity of 9 liters. However, there are no measuring marks on either of the jugs, meaning we cannot determine the exact amount of water filled in either jug. Assuming there is an infinite water supply, how can we measure exactly 5 litres using these unmarked jugs?