SDE - 1

You are the receptionist at a hotel which has 10 floors, numbered from 0 to 9 and each floor has 26 rooms named from ‘A’ to ‘Z’. Being a receptionist your task is to handle booking queries.

You get booking queries in the form of strings of size 3 where 1st character is ‘+’ means room is booked, or ‘-’ means room is freed. Second character represents the floor of the room i.e, ‘0’ to ‘9’. Third character represents the room name i.e, ‘A’ to ‘Z’.

On booking of each room you collect 1 coin from the customer. After the end of all the booking queries you have to count the number of coins you collected.

You may assume that the list describes a correct sequence of bookings in chronological order i.e., only free rooms can be booked, and only booked rooms can be freed.

For Example:-

Consider booking queries to be ["+1A", "+3E", "-1A", "+4F", "+1A", "-3E"]
+1A: Room A on the 1st floor is booked and you collected 1 coin.
+3E: Room E on the 3rd floor is booked and you collected 1 coin.
-1A: Room A on the 1st floor is freed.
+4F: Room F on the 4th floor is booked and you collected 1 coin.
+1A: Room A on the 1st floor is booked and you collected 1 coin.
-3E: Room E on the 3rd floor is freed.
So you collected 4 coins.

This time our favorite Ninja wants to buy a house. But they are unable to count the number of rooms in the house. So they need your help to count the number of rooms.

Note:

A house is represented by a matrix where “\” and “/” represent a wall and blank space is empty space. We will consider two rooms different if we will be unable to reach another room.

Your task is to return the number of rooms. For a better explanation, see the example.

Example:

Input: 
[
  “ /”
  “/\”
]

Output: 3

Explanation: 2 X 2 house is shown below:

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.

You are given a string 'S'. Your task is to partition 'S' such that every substring of the partition is a palindrome. You need to return all possible palindrome partitioning of 'S'.

Note: A substring is a contiguous segment of a string.

For Example:

For a given string “BaaB”
3 possible palindrome partitioning of the given string are:
{“B”, “a”, “a”, “B”}
{“B”, “aa”, “B”}
{“BaaB”}
Every substring of all the above partitions of “BaaB” is a palindrome.