SDE - 1

You are given a linked list of N nodes. Your task is to remove the duplicate nodes from the linked list such that every element in the linked list occurs only once i.e. in case an element occurs more than once, only keep its first occurrence in the list.

For example :

Assuming the linked list is 3 -> 2 -> 3 -> 4 -> 2 -> 3 -> NULL.

Number ‘2’ and ‘3’ occurs more than once. Hence we remove the duplicates and keep only their first occurrence. So, our list becomes : 3 -> 2 -> 4 -> NULL.

You are given an array/list ‘ARR’ of ‘N’ integers. You have to generate an array/list containing squares of each number in ‘ARR’, sorted in increasing order.

For example :

Input:
‘ARR’ = [-6,-3, 2, 1, 5] 

If we take a square of each element then the array/list will become [36, 9, 4, 1, 25].
Then the sorted array/list will be [1, 4, 9, 25, 36].

Output :
[1, 4, 9, 25, 36].

You are given an arbitrary binary tree consisting of N nodes where each node is associated with a certain integer value from 1 to 9. Consider each root to leaf path as a number.

For example:

       1
      /  \
     2    3

The root to leaf path 1->2 represents the number 12.
The root to leaf path 1->3 represents the number 13.

Your task is to find the total sum of all the possible root to leaf paths.

In the above example,

The total sum of all the possible root to leaf paths is 12+13 = 25

Note:

The output may be very large, return the answer after taking modulus with (10^9+7).

Ninja is now bored with numbers and is now playing with characters but hates when he gets repeated characters. Ninja is provided a string, and he wants to return the first unique character in the string.The string will contain characters only from the English alphabet set, i.e., ('A' - 'Z') and ('a' - 'z'). If there is no non-repeating character, print the first character of the string. If there is no non-repeating character, return the first character of the string.

Given an array/list of integer numbers 'CHOCOLATES' of size 'N', where each value of the array/list represents the number of chocolates in the packet. There are ‘M’ number of students and the task is to distribute the chocolate to their students. Distribute chocolate in such a way that:

1. Each student gets at least one packet of chocolate.

2. The difference between the maximum number of chocolate in a packet and the minimum number of chocolate in a packet given to the students is minimum.

Example :

Given 'N' : 5 (number of packets) and 'M' : 3 (number of students)

And chocolates in each packet is : {8, 11, 7, 15, 2}

All possible way to distribute 5 packets of chocolates among 3 students are -

( 8,15, 7 ) difference of maximum-minimum is ‘15 - 7’ = ‘8’
( 8, 15, 2 ) difference of maximum-minimum is ‘15 - 2’ = ‘13’ 
( 8, 15, 11 ) difference of maximum-minimum is ‘15 - 8’ = ‘7’
( 8, 7, 2 ) difference of maximum-minimum is ‘8 - 2’ = ‘6’
( 8, 7, 11 ) difference of maximum-minimum is ‘11 - 7’ = ‘4’
( 8, 2, 11 ) difference of maximum-minimum is ‘11 - 2’ = ‘9’
( 15, 7, 2 ) difference of maximum-minimum is ‘15 - 2’ = 13’
( 15, 7, 11 ) difference of maximum-minimum is ‘15 - 7’ = ‘8’
( 15, 2, 11 ) difference of maximum-minimum is ‘15 - 2’ = ‘13’
( 7, 2, 11 ) difference of maximum-minimum is ‘11 - 2’ = ‘9’

Hence there are 10 possible ways to distribute ‘5’ packets of chocolate among the ‘3’ students and difference of combination (8, 7, 11) is ‘maximum - minimum’ = ‘11 - 7’ = ‘4’ is minimum in all of the above.

You are given a Singly Linked List of integers. You have to return true if the linked list is palindrome, else return false.

A Linked List is a palindrome if it reads the same from left to right and from right to left.

Example:

The lists (1 -> 2 -> 1), (3 -> 4 -> 4-> 3), and (1) are palindromes, while the lists (1 -> 2 -> 3) and (3 -> 4) are not.

Given a binary tree of integers, you are supposed to modify the given binary tree to a sum tree where each node value is replaced by the sum of the values of both left and right subtrees in the given tree. The value of leaf nodes is changed to zero.

Example:

Below is the example showing the input tree and its sum tree.  

You are given a linked list of 'N' nodes. Your task is to reverse the linked list from position 'X' to 'Y'.

For example:

Assuming, the linked list is 10 -> 20 -> 30 -> 40 -> 50 -> 60 -> NULL. X = 2 and Y = 5. On reversing the given linked list from position 2 to 5, we get 10 -> 50 -> 40 -> 30 -> 20 -> 60 -> NULL.

You have been given a Binary Tree of integers. You are supposed to return the reverse of the level order traversal.

For example:

For the given binary tree

The reverse level order traversal will be {7,6,5,4,3,2,1}.

You are given two sorted linked lists. You have to merge them to produce a combined sorted linked list. You need to return the head of the final linked list.

Note:

The given linked lists may or may not be null.

For example:

If the first list is: 1 -> 4 -> 5 -> NULL and the second list is: 2 -> 3 -> 5 -> NULL

The final list would be: 1 -> 2 -> 3 -> 4 -> 5 -> 5 -> NULL

Ninja is stuck in a maze which is in a form of a binary tree. He needs your help in order to get out.

Ninja is presently at the node ‘X’. The only exit points of the maze are the leaf nodes of the tree. You need to tell him the distance to the nearest exit point from his current location. This will help him decide which path he should take in order to escape from the maze.

Example:

Suppose, Ninja is stuck at node 62. The possible exit points in the maze are: 40, 10, and 20. From all the possible exit points the closest ones are 10 and 20 which are at a distance of 1 unit.

You are given an array/list of positive integers ‘NUMS’ of size 'N' and positive integer 'P'. You need to remove the smallest subarray (possibly empty) such that the sum of the remaining elements is divisible by ‘P’.

Your task is to print the length of the smallest subarray that you need to remove, or -1 if it's impossible.

Note:

1. It is not allowed to remove the whole array.
2. A subarray is defined as a contiguous block of elements in the array.

Example:

Suppose given ‘NUMS’ is [3, 1, 4, 2] and ‘P’ is 6.
The sum of the elements in ‘NUMS’ is 10, which is not divisible by 6. We can remove the subarray [4], and the sum of the remaining elements is 6, which is divisible by 6.
So print ‘1’ as a length of the removed subarray [4].

You are given an arbitrary binary tree, a node of the tree, and an integer 'K'. You need to find all such nodes which have a distance K from the given node and return the list of these nodes.

Distance between two nodes in a binary tree is defined as the number of connections/edges in the path between the two nodes.

Note:

1. A binary tree is a tree in which each node has at most two children. 
2. The given tree will be non-empty.
3. The given tree can have multiple nodes with the same value.
4. If there are no nodes in the tree which are at distance = K from the given node, return an empty list.
5. You can return the list of values of valid nodes in any order. For example if the valid nodes have values 1,2,3, then you can return {1,2,3} or {3,1,2} etc.

Example :

Consider this tree above. The target node is 5 and K = 3. The nodes at distance 1 from node 5 are {2}, nodes at distance 2 from node 5 are {1, 4} and nodes at distance 3 from node 5 are {6, 3}.

They asked me about my project. They asked some other questions like what I knew about the company, can I work extra hours like 10-12hrs, whether i have short temper, how will manage to travel to gurugram, etc.