SDE - 1

Ninja has been given two sparse matrices ‘MAT1’ and ‘MAT2’ of integers having size ‘N’ x ‘M’ and ‘M’ x ‘P’, respectively.

A sparse matrix is a matrix that contains very few non-zero elements.

Ninja has to find the matrix formed by the multiplication of ‘MAT1’ and ‘MAT2’. As Ninja is busy with some other tasks so he needs your help. Can you help Ninja to find the matrix formed by the multiplication of ‘MAT1’ and ‘MAT2’?

Note: The number of columns in ‘MAT1’ i.e ‘M’ is equal to the number of rows in ‘MAT2’ i.e ‘M’. It means we can always multiply ‘MAT1’ with ‘MAT2’.

For example:

For the ‘MAT1’ and ‘MAT2’ given below, ‘MAT3’ is the matrix formed by multiplying ‘MAT1’ and ‘MAT2’. 

1. MAT3[0][0] = MAT1[0][0] * MAT2[0][0] + MAT1[0][1] * MAT2[1][0]  ie. 2 * 1 + 1 * 4 = 6
2. MAT3[1][0] = MAT1[1][0] * MAT2[1][0] + MAT1[1][1] * MAT2[1][0] ie. 0 * 6 + 0 * 4 = 0

You have been given an array/list ‘arr’ of length ‘N’, which contains single digit elements at every index. Your task is to return the sum of all elements of the array. But the final sum should also be a single digit.

To keep the output single digit - you need to keep adding the digits of the output number till a single digit is left.

For example:

For the given array [5, 8, 4, 9]

The sum of the elements of the array will be
5 + 8 + 4 + 9 = 26.
Since 26 is not a single-digit number, we will again take the sum of the digits of 26. 
2 + 6 = 8.
Now 8 is a single-digit number. So we will stop here and return 8.

You are given an array ‘ARR’ consisting of ‘N’ strings. Your task is to find the longest common prefix among all these strings. If there is no common prefix, you have to return an empty string.

A prefix of a string can be defined as a substring obtained after removing some or all characters from the end of the string.

For Example:

Consider ARR = [“coding”, ”codezen”, ”codingninja”, ”coders”]
The longest common prefix among all the given strings is “cod” as it is present as a prefix in all strings. Hence, the answer is “cod”.

If a milkman earns 12 Rs profit per litre of milk then the total profit he will earn from selling 35 litre of milk is?

Find the total rows where the words on left and right side are exactly same

Bangalore Banglore
Chennai Chennai
12,45 Gate 12,46 GAte
Castle Castle

interviewer asked me to implement a feature to rate the tips and add feedback on tips to update their rating based on feedback.

discussion happened around my previous internship experience

Asked about my project i.e ( tips to users ) and ask me to to add other features to my project and how I will add them

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].

Design a Miniature Railway city zoo that can be controlled by children using a controller with 3 inputs (select the train color, starting point, and ending point). This was an open-ended problem and I have to define things from scratch with proper reasoning.

why I want to join Trilogy

He asked me things like what were the most challenging problems I have solved and other general HR questions