SDE - 1

You are given ‘N’ items. Each item either doesn’t belong to any group or belongs to exactly one group out of ‘M’ groups. For each item, you are also given a list, ‘BEFORE’, containing items that should appear before this item in the final sorted list.

Your task is to sort these items in an order which follows the following rules :

The items belonging to the same group must be ordered adjacent to each other.
The item which does not belong to any group can be placed anywhere. 
Each item appearing in BEFORE[i] must be placed before the ith item in the sorted list.

You are given a singly linked list of integers.

Your task is to swap every two adjacent nodes, and return the head of the modified, linked list.

For Example:

We have a linked list 1->2->3->4->5->6->7 and so on. You are supposed to swap pairs of a linked list like swap (1,2), (3,4), (5,6), and so on.

Note:

1. You may not modify the data in the list’s nodes; only nodes themselves may be changed. Because imagine a case where a node contains many fields, so there will be too much unnecessary swap.

2. If a pair of a node does not exist, then leave the node as it is.

You have been given a Binary Tree of integers. You are supposed to return the top view of the given binary tree.

Top view of the binary tree is the set of nodes which are visible when we see the tree from the top.

For example:

For the given binary tree

The top view of the tree will be {10, 4, 2, 1, 3, 6}.

You are given a string 'S'. Your task is to check whether the string is palindrome or not. For checking palindrome, consider alphabets and numbers only and ignore the symbols and whitespaces.

Note :

String 'S' is NOT case sensitive.

Example :

Let S = “c1 O$d@eeD o1c”.
If we ignore the special characters, whitespaces and convert all uppercase letters to lowercase, we get S = “c1odeedo1c”, which is a palindrome. Hence, the given string is also a palindrome.

Questions were mainly related to how your personality is such as hobbies etc.