Software Engineer

Given an integer ‘N’ representing the number of pairs of parentheses, Find all the possible combinations of balanced parentheses with the given number of pairs of parentheses.

Note :

Conditions for valid parentheses:
1. All open brackets must be closed by the closing brackets.

2. Open brackets must be closed in the correct order.

For Example :

()()()() is a valid parentheses.
)()()( is not a valid parentheses.

Write a program to do basic string compression. For a character which is consecutively repeated more than once, replace consecutive duplicate occurrences with the count of repetitions.

Example:

If a string has 'x' repeated 5 times, replace this "xxxxx" with "x5".
The string is compressed only when the repeated character count is more than 1.

Note:

Consecutive count of every character in the input string is less than or equal to 9. You are not required to print anything. It has already been taken care of. Just implement the given function and return the compressed string.

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 permutation 'A' of length 'N'. You can apply the following operation any number of times which costs 1 coin for each operation.

Select any subarray of length at most 'N' - 1 and rearrange the elements in any order.

Return the minimum number of coins required to sort the permutation in increasing order.

A permutation is an array in which each element from 1 to 'N' occurs exactly once.

For Example:-

Let 'N' = 5, 'A' = [1, 2, 3, 5, 4].
We can apply the operation to the subarray from index 4 to 5 (1-based indexing).
So our answer is 1.