50+ Dattson & Co Interview Questions and Answers

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 lis...read more

Given an array of numbers, find the maximum sum of any contiguous subarray of the array.

For example, given the array [34, -50, 42, 14, -5, 86], the maximum sum would be 137, since we would ...read more

You have been given a grid containing some oranges. Each cell of this grid has one of the three integers values:

Value 0 - representing an empty cell.

Value 1 - representing a fresh orange.

...read more

You have been given a linked list of integers. Your task is to write a function that deletes a node from a given position, 'POS'.

Note :

Assume that the Indexing for the linked lis...read more

Given a linked list having two pointers in each node. The first one points to the next node of the list, however, the other pointer is random and can point to any node of th...read more

You are given an array of integers. You need to sort the array in ascending order using quick sort.

Quick sort is a divide and conquer algorithm in which we choose a pivot point and partition the arr...read more

You have been given a binary tree of 'N' nodes. Print the Spiral Order traversal of this binary tree.

For example

For the given binary tree [1, 2, 3, -1, -1, 4, 5, -1, -1,...read more

A palindrome string is one that reads the same backward as well as forward. Given a string 'STR', you need to tell the minimum number of characters needed to insert...read more

You have been given a Binary Tree of 'N' nodes, where the nodes have integer values. Your task is to print the zigzag traversal of the given tree.

Note:

In zigzag order, level 1 is printed from...read more

You have been given two Strings “STR1” and “STR2” of characters. Your task is to find the length of the longest common subsequence.

A String ‘a’ is a subsequence of a String ‘b’ if ‘a’...read more

There is a one-dimensional garden of length 'N'. On each of the positions from 0 to 'N', there is a fountain, and this fountain’s water can reach up to a certain range as explained further. In ...read more

You have been given an array/list ARR consisting of ‘N’ elements. Each element in the array is either 0, 1 or 2.

Now, your task is to sort this array/list in increasing order. For ...read more

You are given a Singly Linked List of integers and a reference to the node to be deleted. Every node of the Linked List has a unique value written on it. Your task is to delete that ...read more

For a given array/list of integers of size N, print the Next Greater Element(NGE) for every element. The Next Greater Element for an element X is the first element on the right side of X in ...read more

You have been given an array/list of strings 'STR_LIST'. You are supposed to return the strings as groups of anagrams such that strings belonging to a particular group are anagrams of one...read more

You have been given an arbitrary binary tree and a node of this tree. You need to find the inorder successor of this node in the tree.

The inorder successor of a node in a binary tree is that no...read more

Given a ‘N’ * ’M’ maze with obstacles, count and return the number of paths to reach the right-bottom cell from the top-left cell. A cell in the given maze has a value -1 if it is a blockage or de...read more

You have been given a singly Linked List of integers. Your task is to delete the middle node of this List.

Note:

1. If there is no middle node in the list to delete, return an empty list (i.e...read more

You have been given two singly Linked Lists, where each of them represents a positive number without any leading zeros.

Your task is to add these two numbers and print the summation in the ...read more

Given a sequence of numbers ‘ARR’. Your task is to return a sorted sequence of ‘ARR’ in non-descending order with help of the merge sort algorithm.

Example :

Merge Sort Algorithm - Merge sort is a Di...read more

You are given an array of integers 'ARR' of length 'N' and an integer Target. Your task is to return all pairs of elements such that they add up to Target.

Note:

We cannot use the element at a given ind...read more

You are given an array 'ARR' consisting of 'N' positive numbers and sorted in non-decreasing order, and your task is to find the smallest positive integer value that cannot be represented a...read more

You are given a N x 2 2-D array 'Jobs' of 'N' jobs where Jobs[i][0] denote the deadline of i-th job and Jobs[i][1] denotes the profit associated with i-th job.

You will make a certain prof...read more

Ninja is stuck in a maze which is in a form of a binary tree. He needs your help in order to get out.

Ninja is presently at the node ‘X’. The only exit points of the maz...read more

You have been given two arrays, 'AT' and 'DT', representing the arrival and departure times of all trains that reach a railway station.

Your task is to find the minimum numbe...read more

Given a binary tree. Your task is to print the bottom right view of the binary tree.

Bottom right view, on viewing the given binary tree at the angle of 45 degrees from the botto...read more

You are given a list of ‘transactions’ between ‘n’ number of friends. who have to give each other money. The list consists of data of receiver, sender, and transaction.

Your task is to minimiz...read more

You are given a sorted array ‘A’ and an integer ‘X’. Your task is to find and return the floor value of ‘X’ in the array.

The floor value of ‘X’ in array ‘A’ is the largest element in the array ...read more

Given a sequence of ‘N’ space-separated non-negative integers A[1],A[2],A[3],......A[i]…...A[n]. Where each number of the sequence represents the height of the line drawn at point 'i'. ...read more

You have been given an array/list ARR consisting of ‘N’ integers. You are also given a positive integer ‘K’.

Your task is to find the lexicographically smallest ARR that can be o...read more

Given an array ARR of N integers and an integer S. The task is to find whether there exists a subarray(positive length) of the given array such that the sum of elements of the subar...read more

A person has 3000 bananas and a camel. He wants to transport the maximum number of bananas to a destination 1000 KMs away, using only the camel as a mode of transportation. The camel cann...read more

Introduction of all my projects.
What is serialization and deserialization in Java?
Deep go through all the projects and technology used in projects Challenges you have faced and how did...read more

• Flow kotlin

• Android 10 to Android 11 migration support

• Kotlin cons and pros

• Dagger! should we use it?

• MVVM explain

• Android versions with their features and specialities

• Activity...read more

Multithreading Concepts? How thread works in java?
Difference in sleep() and wait().
Print even odd using two threads. What is synchronization Block & why it is used?

He asked me some output questions which were based on JavaScript fundamentals like hoisting, arrow function etc.
Some questions were from Redux. At that time I didn't have any experien...read more

Given a binary tree (not a binary search tree) and two values say n1 and n2, write a program to find the least common ancestor.

Main questions that were asked were based on callbacks, promises, Closures, Event loop.
Some output guessing questions :
1. Difference between let, var, const
2. ES6 features
3. Hoisting
4. Rest,...read more

Questions about scheduling algorithms, dead lock, synchronization etc. were asked.

He asked me some JavaScript questions again and also told me about the work culture of his team. It was more like an open discussion with some tech questions

What is sharding?