Software Engineer

Ritik is stuck on a problem for the past few days. He has a stack 'S' of integers and his friend told him to sort the stack recursively.

Help Ritik to solve his problem so that he can show it off to his friend.

Note:

1. Looping through the stack is not allowed.
2. You need to return a stack that is sorted in descending order.

For example:

Given stack 'S' = 1 3 2 
The output will be 3 2 1 since it is the sorted order.

Given a text and a wildcard pattern of size N and M respectively, implement a wildcard pattern matching algorithm that finds if the wildcard pattern is matched with the text. The matching should cover the entire text not partial text.

The wildcard pattern can include the characters ‘?’ and ‘*’

 ‘?’ – matches any single character 
 ‘*’ – Matches any sequence of characters(sequence can be of length 0 or more)

Is government doing the right thing by divesting public sector companies?

You are given a Doubly Linked List of integers and a positive integer 'K' representing the group size. Modify the linked list by reversing every group of 'K' nodes in the linked list.

A doubly linked list is a type of linked list that is bidirectional, that is, it can be traversed in both directions, forward and backward. 

Note:

If the number of nodes in the list or in the last group is less than K, just reverse the remaining nodes. 

Example:

Linked list: 8 9 10 11 12
K: 3 

Output: 10 9 8 12 11

We reverse the first K (3) nodes. Now, since the number of nodes remaining in the list (2) is less than K, we just reverse the remaining nodes (11 and 12).  

You have been given an integer array/list (ARR) of size N. You have to return an array/list PRODUCT such that PRODUCT[i] is equal to the product of all the elements of ARR except ARR[i]

 Note :

Each product can cross the integer limits, so we should take modulo of the operation. 

Take MOD = 10^9 + 7 to always stay in the limits.

Follow up :

Can you try solving the problem in O(1) space?