SDE - 1

You are given N number of intervals, where each interval contains two integers denoting the start time and the end time for the interval.

The task is to merge all the overlapping intervals and return the list of merged intervals sorted by increasing order of their start time.

Two intervals [A,B] and [C,D] are said to be overlapping with each other if there is at least one integer that is covered by both of them.

For example:

For the given 5 intervals - [1, 4], [3, 5], [6, 8], [10, 12], [8, 9].

Since intervals [1, 4] and [3, 5] overlap with each other, we will merge them into a single interval as [1, 5].

Similarly, [6, 8] and [8, 9] overlap, merge them into [6,9].

Interval [10, 12] does not overlap with any interval.

Final List after merging overlapping intervals: [1, 5], [6, 9], [10, 12].

Kevin has written some integers on a paper. He then selects some integers and draws a line between them. Fortunately, his diagram represents a binary tree. Today, his friend challenged him to find the paths that start from root and end at the leaf in his diagram whose sum is exactly equal to the number ‘K’. But, Kevin has another important piece of work and so, he appoints you to do his task.

All you have to do is to find the paths in his diagram whose sum is exactly equal to the number ‘K’.

For Example:

Consider the above binary tree. If ‘K’ is 15 then the required paths are [5, 6, 4] and [5, 15, -5].

You are given a binary tree with ‘N’ nodes.

Your task is to find the “Maximum Path Sum” for any path.

Note :

1. A ‘path’ is a sequence of adjacent pair nodes with an edge between them in the binary tree.
2. The ‘path’ doesn’t need to pass through the root.
3. The ‘path sum’ is the sum of the node’s data in that path. 

Ninja has to implement a data structure ”TRIE” from scratch. Ninja has to complete some functions.

1) Trie(): Ninja has to initialize the object of this “TRIE” data structure.

2) insert(“WORD”): Ninja has to insert the string “WORD”  into this “TRIE” data structure.

3) countWordsEqualTo(“WORD”): Ninja has to return how many times this “WORD” is present in this “TRIE”.

4) countWordsStartingWith(“PREFIX”): Ninjas have to return how many words are there in this “TRIE” that have the string “PREFIX” as a prefix.

5) erase(“WORD”): Ninja has to delete one occurrence of the string “WORD” from the “TRIE”.

Note:

1. If erase(“WORD”) function is called then it is guaranteed that the “WORD” is present in the “TRIE”.

2. If you are going to use variables with dynamic memory allocation then you need to release the memory associated with them at the end of your solution.

Can you help Ninja implement the "TRIE" data structure?

You are given ‘n’ cities, some of which are connected by bidirectional roads. You are also given an ‘n x n’ matrix i.e. ‘roads’, where if city ‘i’ and ‘j’ are connected by a road then ‘roads[i][j]'= 1, otherwise ‘roads[i][j]' = 0.

A province is a group of cities that are either directly or indirectly connected to each other through roads.

The goal is to count and return the total number of such provinces in the given matrix.

Example:

n = 4, roads = [ [1, 1, 1, 0],
                 [1, 1, 1, 0],
                 [1, 1, 1, 0],
                 [0, 0, 0, 1] ]

So, there are ‘2’ provinces.

Note:

1. A city is connected to itself. So, for every city ‘i’, ‘roads[i][i] = 1’.

I had worked on AWS and deployed containers on AWS Fargate which is a serverless offering from AWS. Since he was from Cloud domain he asked me regarding basics of Docker and some questions on basis of cloud. Discussion revolved around scaling infrastructure, networking and monitoring the infrastructure (CloudWatch):
- What is Docker?
- What is Serverless?
- Difference between Containerization and Virtualization
- How to handle networking between containers?
- What is Saas, Iaas, Paas?

Given a matrix ‘UNIVERSE’ with 3 rows and ‘N’ columns, with the characters { # , * , . } and these characters represent a cluster of stars and galaxies in space. Stars are represented by ‘*’ symbol. The ‘.’ symbol represents empty space.

We define a constellation as a 3x3 matrix which contains stars in the shape of vowels. A group of constellations is defined as a galaxy. Note that a galaxy may contain many stars but they will never be overlapping. Two galaxies are separated by a column of ‘#’.

Given the ‘UNIVERSE’ matrix, print a string which denotes all the vowels formed by stars and ‘#’ present in the matrix.

A looks like this :

. * .
* * *
* . *

E looks like this :

* * *
* * *
* * *

I looks like this :

* * *
. * .
* * *

O looks like this :

* * *
* . *
* * *

U looks like this :

* . *
* . *
* * *

Note :

It is guaranteed that no two constellations are overlapping.