SDE - 1

You are given a matrix 'MAT' of size ‘N’ * ‘M’, where ‘N’ is the number of rows and ‘M’ is the number of columns. Value ‘0’ in a cell represents that the cell is set on fire initially, (at time t = ‘0’), and the cells which don’t have fire initially have value = ‘1’, and are called safe cells.

If a cell is on fire, then in one second the fire will expand to its adjacent cells (left, right, top, bottom) if they are not already on fire.

You are given the position of a person as integers ‘X’ and ‘Y’ denoting the cell (‘X’, ‘Y’). In one second the person can move from its current cell to any one of its adjacent cells, provided they are not on fire.

You have to determine if the person can move through the matrix to one of the escape cells without burning himself i.e. without going through the fire cells. If it’s possible, return time taken, else return -1.

Note:

1. Escape cells in this problem are all such cells that lie on the edge of the matrix but not on the corner. i.e all such cells which are in the first row, first column, last row, and last column excluding the four corner cells are considered as valid escape cells.

2. A cell once set on fire continues to remain on fire till the end.

3. Note that rows are indexed from 0 to ‘N’ - 1 and columns are indexed from 0 to ‘M’ - 1.

4. The escape cells may also be initially on fire or can catch fire from some neighboring cell.

Alex has a computer with ‘K’ memory spaces. He has a list of ‘N’ different document downloads that he would like to do, each of which consumes some unique memory usage. He also has ‘M’ computer games, each of which consumes some unique memory usage. His computer can allow at most one download and at most one game to run simultaneously, provided that the sum of memory usages doesn’t exceed ‘K’. Alex wants to play at most one game and complete at most one download so that the total memory usage is maximum.

Given a list ‘download’ and a list ‘game’, help Alex find out the number of pairs of downloads and games such that the sum of memory usages is maximum. It can also be possible that Alex only plays a game or performs a download at a time.

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 are given a 'Binary Tree'.

Return the bottom view of the binary tree.

Note :

1. A node will be in the bottom-view if it is the bottom-most node at its horizontal distance from the root. 

2. The horizontal distance of the root from itself is 0. The horizontal distance of the right child of the root node is 1 and the horizontal distance of the left child of the root node is -1. 

3. The horizontal distance of node 'n' from root = horizontal distance of its parent from root + 1, if node 'n' is the right child of its parent.

4. The horizontal distance of node 'n' from root = horizontal distance of its parent from the root - 1, if node 'n' is the left child of its parent.

5. If more than one node is at the same horizontal distance and is the bottom-most node for that horizontal distance, including the one which is more towards the right.

Example:

Input: Consider the given Binary Tree:

Output: 4 2 6 3 7

Explanation:
Below is the bottom view of the binary tree.

1 is the root node, so its horizontal distance = 0.
Since 2 lies to the left of 0, its horizontal distance = 0-1= -1
3 lies to the right of 0, its horizontal distance = 0+1 = 1
Similarly, horizontal distance of 4 = Horizontal distance of 2 - 1= -1-1=-2
Horizontal distance of 5 = Horizontal distance of 2 + 1=  -1+1 = 0
Horizontal distance of 6 = 1-1 =0
Horizontal distance of 7 = 1+1 = 2

The bottom-most node at a horizontal distance of -2 is 4.
The bottom-most node at a horizontal distance of -1 is 2.
The bottom-most node at a horizontal distance of 0 is 5 and 6. However, 6 is more towards the right, so 6 is included.
The bottom-most node at a horizontal distance of 1 is 3.
The bottom-most node at a horizontal distance of 2 is 7.

Hence, the bottom view would be 4 2 6 3 7

Given a string 'S' and a list 'wordList' that consists of 'N' distinct words. Let 'Wi' denote word at index 'i' in 'wordList'. For each word 'Wi' in 'wordList', you need to determine whether it is present in string 'S' or not. Return a boolean array, where a boolean value at index ‘i’ represents whether the word ‘Wi’ is present in the string ‘S’ or not.

You are given two positive integers ‘N’ and ‘K’. You have to find the ‘K’-th factor of ‘N’, where the ‘K’-th factor is the ‘K’-th number in a sequence of all the factors of ‘N’ arranged in ascending order.

For example:

If N = 12 and K = 5, then we have to find the 5’th factor of 12 out of the list of all factors of 12 : [1, 2, 3, 4, 6, 12], the 5’th factor in the list is 6. Hence, the output is 6.

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Ninjas is practicing problems on the linked list. He came across a problem in which he has given a linked list of ‘N’ nodes and two integers, ‘LOW’ and ‘HIGH’. He has to return the linked list ‘HEAD’ after reversing the nodes between ‘LOW’ and ‘HIGH’, including the nodes at positions ‘LOW’ and ‘HIGH’.

Was mostly discussing on the projects that I did. With some alteration to them as I could not exactly tell what the flow of the project was. So the interviewer introduced to me the scenarios in the project and told me how the system would look like then.