SDE - 1

Given a singly linked list of integers. Your task is to return the head of the reversed linked list.

For example:

The given linked list is 1 -> 2 -> 3 -> 4-> NULL. Then the reverse linked list is 4 -> 3 -> 2 -> 1 -> NULL and the head of the reversed linked list will be 4.

Follow Up :

Can you solve this problem in O(N) time and O(1) space complexity?

You are given two integers, ‘N’ and ‘V’. You need to construct a string having length ‘N’ and numeric value ‘V’.

The numeric value of a character is determined by its position in alphabets( 1- indexed)

For Example-

The numeric value of ‘a’ is 1, ‘b’ is 2.

The numeric value of a string is determined by adding the numeric value of all its characters.

For Example -

The numeric value of “bde” is 2 + 4 + 5, i.e. 11.

Example:

If 'N' = 3 and 'V' = 10, you need to construct string as “aah".

You have been given a binary tree of integers. You are supposed to find the left view of the binary tree. The left view of a binary tree is the set of all nodes that are visible when the binary tree is viewed from the left side.

Example:

The left view of the above binary tree is  {5, 7, 14, 25}.

You are given a board of‘ ‘N’ size. You can roll a dice and jump from position ‘i’ to i + 1, i + 2, i + 3, i + 4, i + 5, and i + 6 respectively. An array ‘connections’ of size ‘M’ is also provided where you can visit from the point ‘connections[i][0]’ to ‘connections[i][1]’ directly. Your task is to find the minimum number of dice rolls to reach from 1 to ‘N’ on the board.

For example:

Consider 'N' = 10, 'connections' = [[2, 10]]

We can go from 1 -> 2 with the help of dice (the number of operations increases by 1).
We can go from 2 -> 10 as 2 is directly connected to 10. No operation is required for this.
Hence the answer is 1.