SDE - 1

Imagine a group of people meeting each other for the first time, and in keeping with protocol, each person must greet and elbow bump every other person once.
If there were seven people in the group, how many elbow bumps would occur in total?
Also outline, as a short note in the comment section, the process you used to come to this conclusion.

Ninja has been given two sorted integer arrays/lists ‘ARR1’ and ‘ARR2’ of size ‘M’ and ‘N’. Ninja has to merge these sorted arrays/lists into ‘ARR1’ as one sorted array. You may have to assume that ‘ARR1’ has a size equal to ‘M’ + ‘N’ such that ‘ARR1’ has enough space to add all the elements of ‘ARR2’ in ‘ARR1’.

For example:

‘ARR1’ = [3 6 9 0 0]
‘ARR2’ = [4 10]
After merging the ‘ARR1’ and ‘ARR2’ in ‘ARR1’. 
‘ARR1’ = [3 4 6 9 10]

You are given two binary trees with 'n' and 'm' nodes respectively.

You need to return true if the two trees are identical. Otherwise, return false.

Example:

For the trees given below:- 

The given trees are identical as:-
1. The number of nodes in both trees is the same. 
2. The number of edges in both trees is the same. 
3. The data for root for both the trees is the same i.e 5. 
4. The data of root -> left (root’s left child) for both the trees is the same i.e 2.
5. The data of root -> right (root’s right child) for both the trees is the same i.e 3.
6. The data of root -> right -> left ( left child of root’s right child) for both the trees is the same i.e 6.
7. Nodes with data 2 and 6 are the leaf nodes for both the binary trees. 

You are given an array 'ARR' of 'N' positive integers. You need to find the minimum number of operations needed to make all elements of the array equal. You can perform addition, multiplication, subtraction or division with any element on an array element.

Addition, Subtraction, Multiplication or Division on any element of the array will be considered as a single operation.

Example:

If the given array is [1,2,3] then the answer would be 2. One of the ways to make all the elements of the given array equal is by adding 1 to the array element with value 1 and subtracting 1 from the array element with value 3. So that final array would become [2,2,2]. 

You are given the head node of a singly linked list 'head'. Your task is to modify the linked list in such a way that all the even valued nodes appear before the all odd valued node and order of nodes remain the same.

Example :-

The given singly linked list is  6 -> 5 -> 3 -> 4 -> 7 -> 1 -> 2 

The modified linked list should have all even values in starting and odd values in the end.

You have been given a Binary Tree of 'N'

nodes, where the nodes have integer values.

Your task is to return the ln-Order, Pre-Order, and Post-Order traversals of the given binary tree.

For example :

For the given binary tree:

The Inorder traversal will be [5, 3, 2, 1, 7, 4, 6].
The Preorder traversal will be [1, 3, 5, 2, 4, 7, 6].
The Postorder traversal will be [5, 2, 3, 7, 6, 4, 1].