Data Analyst

Two trains are on the same track and they are coming toward each other. The speed of the first train is 50 km/h and the speed of the second train is 70 km/h. A bee starts flying between the trains when the distance between two trains is 100 km. The bee first flies from the first train to the second train. Once it reaches the second train, it immediately flies back to the first train … and so on until trains collide. Calculate the total distance traveled by the bee. The speed of the bee is 80 km/h. 

Given a maze in the form of a binary rectangular matrix of size M*N, where each element can either be 0 or 1, the task is to find the length of the shortest path in a maze from a given source cell to a destination cell.

The path can only be created out of a cell if its value is 1 and at any given moment, we can only move one step in one of the four directions. The valid moves are:

Up: (x, y) -> (x - 1, y)
Left: (x, y) -> (x, y - 1)
Down: (x, y) -> (x + 1, y)
Right: (x, y) -> (x, y + 1)

If there is no path from a given source cell to a destination cell, return -1.

For example :

consider the binary matrix below. If source = (0, 0) and destination = (3, 4), the shortest path from source to destination has length 11.

You are given a string ‘S’. You are also given ‘M’ integers in an array ‘A’. You perform ‘M’ operations on this string. The operations are given in an array ‘A’ of size ‘M’.

You perform the operations in the order they appear in the array ‘A’. In the ‘i’th operation, you reverse the substring of ‘S’ from the position ‘A[i]’ to ‘len(S)’ - ‘A[i]’ - 1 (0 based).

Your task is to find the string after performing all the operations.

Example :

‘S’ = “aabcd”, ‘M’ = 2, ‘A’ = [0, 1]
After 1st operation i.e, reversing from [0, 4], ‘S’ = “dcbaa”.
After 2nd operation i.e, reversing from [1, 3], ‘S’ = “dabca”.
Hence, the answer is “dabca”.

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.