SDE - 1

You are given an array of integers ‘NUMS’. The beauty of this array can be defined as:

The sum of absolute difference of each two consecutive elements.

In one operation you can reverse one subarray of ‘NUMS’. Your task is to find maximum beauty by performing the operation exactly once.

You are given a linked list of 'n' nodes and an integer 'k', where 'k' is less than or equal to 'n'.

Your task is to reverse the order of each group of 'k' consecutive nodes, if 'n' is not divisible by 'k', then the last group of nodes should remain unchanged.

For example, if the linked list is 1->2->3->4->5, and 'k' is 3, we have to reverse the first three elements, and leave the last two elements unchanged. Thus, the final linked list being 3->2->1->4->5.

Implement a function that performs this reversal, and returns the head of the modified linked list.

Example:

Input: 'list' = [1, 2, 3, 4], 'k' = 2

Output: 2 1 4 3

Explanation:
We have to reverse the given list 'k' at a time, which is 2 in this case. So we reverse the first 2 elements then the next 2 elements, giving us 2->1->4->3.

Note:

All the node values will be distinct.

You are given a linked list having ‘n’ nodes and an integer ‘k’.

You have to rotate the linked list to the right by ‘k’ positions .

Example :

Input: linked list = [1 2 3 4] , k = 2

Output: 3 4 1 2

Explanation:
We have to rotate the given linked list to the right 2 times. After rotating it to the right once it becomes 4->1->2->3. After rotating it to the right again, it becomes 3->4->1->2. 

You have been given a sorted array/list 'arr' consisting of ‘n’ elements. You are also given an integer ‘k’.

Now the array is rotated at some pivot point unknown to you.

For example, if 'arr' = [ 1, 3, 5, 7, 8], then after rotating 'arr' at index 3, the array will be 'arr' = [7, 8, 1, 3, 5].

Now, your task is to find the index at which ‘k’ is present in 'arr'.

Note :

1. If ‘k’ is not present in 'arr', then print -1.
2. There are no duplicate elements present in 'arr'. 
3. 'arr' can be rotated only in the right direction.

Example:

Input: 'arr' = [12, 15, 18, 2, 4] , 'k' = 2

Output: 3

Explanation:
If 'arr' = [12, 15, 18, 2, 4] and 'k' = 2, then the position at which 'k' is present in the array is 3 (0-indexed).

Reverse the given string word wise. That is, the last word in given string should come at 1st place, last second word at 2nd place and so on. Individual words should remain as it is.

You are given a Binary Tree of 'n' nodes.

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

Find the top view of the given binary tree, from left to right.

Example :

Input: Let the binary tree be:

Output: [10, 4, 2, 1, 3, 6]

Explanation: Consider the vertical lines in the figure. The top view contains the topmost node from each vertical line.

Difference between delete and truncate. (Learn)