30+ Dunzo Interview Questions and Answers

Given a matrix of coins, Alice and Bob have to collect maximum coins with certain conditions.

• Alice starts from top left corner and Bob starts from top right corner

• They can move to (i+1, j+1) or (i+1, j-1) or (i+1, j)

• They have to collect all the coins that are present at a cell

• If Alice has already collected coins of a cell, then Bob gets no coins if goes through that cell again

Count the number of arithmetic subarrays in an array.

• An arithmetic subarray has 3 or more elements with the same difference between consecutive elements.

• Loop through the array and check for all possible subarrays with 3 or more elements.

• If the difference between consecutive elements is the same, increment the count.

• Return the count for each test case.

Given a binary matrix, find the distance of the nearest cell having 1 in the matrix for each cell.

• Use BFS to traverse the matrix and find the nearest cell having 1 for each cell.

• Initialize the output matrix with maximum possible distance.

• If the current cell has 1, distance is 0, else update distance based on the nearest cell having 1.

Determine the state of asteroids after collisions occur.

• Iterate through the array of asteroids and simulate collisions between adjacent asteroids.

• Use a stack to keep track of remaining asteroids after collisions.

• Handle cases where asteroids moving in opposite directions collide and destroy each other.

• Handle cases where asteroids moving in the same direction do not collide.

Find two lines to form a container with maximum water area on a Cartesian plane.

• Iterate through the array from both ends to find the maximum area.

• Calculate the area using the formula: (min(height[left], height[right]) * (right - left)).

• Update the pointers based on the height of the lines to maximize the area.

Count the number of subsequences with odd and even sums in a given array of positive integers modulo 10^9 + 7.

• Use dynamic programming to keep track of the count of subsequences with odd and even sums.

• Consider the parity of each element in the array to determine the count of subsequences with odd and even sums.

• Apply modulo 10^9 + 7 to handle large resulting numbers.

• Example: For input [1, 2, 3], there are 3 subsequences with odd sums and 4 subsequences with even sums.

Find the minimum cost to reduce an array to a single element by merging adjacent elements with their sum.

• Iteratively merge adjacent elements to minimize total cost

• Choose pairs to merge strategically to reduce cost

• Calculate sum of adjacent elements and update array size

Given a string and a dictionary, generate all possible sentences by adding spaces between words from the dictionary.

• Use backtracking to generate all possible sentences by recursively adding words from the dictionary to the current sentence.

• Check if the current substring of the input string exists in the dictionary, if so, add it to the current sentence and continue recursively.

• When the entire input string is processed, add the current sentence to the result list.

• Repeat the pr...read more

Find the largest area of a submatrix containing only 1's in a binary matrix.

• Iterate over each cell in the matrix and calculate the maximum area of submatrix with all 1's ending at that cell.

• Use dynamic programming to keep track of the maximum area ending at each cell.

• Update the maximum area as you iterate through the matrix.

• Return the overall maximum area found in the matrix.

Implement a wildcard pattern matching algorithm to determine if a given wildcard pattern matches a text string completely.

• Create a dynamic programming matrix to store intermediate results

• Handle cases for '?' and '*' characters separately

• Check if the characters match or '*' can be used to match any sequence of characters

Convert a binary tree into its mirror tree by interchanging left and right children of non-leaf nodes.

• Traverse the binary tree in a recursive manner and swap the left and right children of each non-leaf node.

• Use a temporary variable to swap the children of each node.

• Ensure to handle cases where a node may have only one child or no children.

• Implement the function to convert the given binary tree to its mirror tree in place.

Identify starting indices of anagram substrings of 'PTR' in 'STR'.

• Use a sliding window approach to check for anagrams of 'PTR' in 'STR'.

• Create a frequency map of characters in 'PTR' and 'STR' to compare.

• Slide the window along 'STR' and check if the frequency maps match.

• Return the starting indices where anagrams are found.

The task is to determine whether a given undirected graph is bipartite or not.

• Create a function to check if the graph can be colored using two colors without any adjacent vertices sharing the same color.

• Use graph coloring algorithms like BFS or DFS to determine if the graph is bipartite.

• Check for odd-length cycles in the graph, as a bipartite graph cannot have odd-length cycles.

• Consider using a boolean array to keep track of visited vertices and their colors while traversing ...read more

The task is to find the next greater element for each element in an array to its right, if no greater element exists return -1.

• Use a stack to keep track of elements for which the next greater element is not found yet.

• Iterate through the array from right to left, popping elements from the stack until a greater element is found.

• Store the next greater element for each element in a separate array.

The problem involves finding the length of the longest common subsequence between two given strings.

• Use dynamic programming to solve the problem efficiently.

• Create a 2D array to store the lengths of common subsequences of substrings.

• Iterate through the strings to fill the array and find the length of the longest common subsequence.

• Return the length of the longest common subsequence for each test case.

Convert the given array into a min-binary heap by following min-heap properties.

• Iterate through the array and heapify each node starting from the last non-leaf node to the root.

• For each node, compare it with its children and swap if necessary to maintain min-heap property.

• Continue this process until the entire array satisfies the min-heap property.

Print the left view of a binary tree, containing nodes visible from the left side.

• Traverse the tree level by level, keeping track of the leftmost node at each level

• Use a queue for level order traversal and a map to store the leftmost nodes

• Print the values of leftmost nodes stored in the map as the left view of the tree

Implement a Trie data structure supporting insert and search operations efficiently.

• Implement a Trie class with insert and search methods.

• Use a nested class Node to represent each node in the Trie.

• For insert operation, iterate through each character in the word and create nodes as needed.

• For search operation, traverse the Trie based on the characters in the word to check for existence.

• Return 'TRUE' if the word is found in the Trie, 'FALSE' otherwise.

The task is to determine if a given string consisting of parentheses is balanced or not.

• Use a stack data structure to keep track of opening parentheses

• Iterate through the string and push opening parentheses onto the stack and pop when encountering a closing parenthesis

• If at the end the stack is empty, the string is balanced, otherwise it is not

Print the left view of a binary tree given in level order form.

• Traverse the tree level by level and print the first node of each level (leftmost node)

• Use a queue to keep track of nodes at each level

• Time complexity should be O(n) where n is the number of nodes in the tree

Implementing undo and redo operations for MS Word

• Maintain a stack for undo operations and another stack for redo operations

• Whenever a change is made, push the previous state onto the undo stack

• When undo is triggered, pop the state from undo stack and push it onto redo stack

• When redo is triggered, pop the state from redo stack and push it onto undo stack

• Ensure to update the document state accordingly after each undo or redo operation

It is not appropriate to refer to employees by their skin color. All employees should be treated equally and with respect.

• It is important to avoid using language that could be perceived as discriminatory or offensive

• Focus on individual performance and behavior rather than skin color

• Provide equal opportunities for all employees to succeed

• Create a culture of inclusivity and diversity

• Train managers and employees on diversity and inclusion best practices

Ideal EPH for a city depends on various factors such as population, geography, climate, and infrastructure.

• EPH stands for 'Events Per Hour', which refers to the number of emergency incidents that occur in a city per hour.

• The ideal EPH for a city can vary depending on the size of the population, the geography of the area, the climate, and the infrastructure available to respond to emergencies.

• For example, a city with a high population density and limited emergency services may...read more

Tools required for a smooth operation include inventory management software, communication tools, and employee scheduling software.

• Inventory management software to track stock levels and ensure timely restocking

• Communication tools such as email, phone, and messaging apps to keep in touch with employees and customers

• Employee scheduling software to manage shifts and ensure adequate staffing levels

• Point of sale (POS) system to process transactions and track sales data

• Security sy...read more

The overall supply needed for N number of tasks depends on the specific requirements of each task.

• The supply needed for each task should be assessed individually

• Factors such as task duration, complexity, and required resources should be considered

• The total supply needed can be calculated by adding up the supply requirements for each task

• Regular monitoring and adjustment of supply levels may be necessary

I am currently earning INR 8 lakhs per annum and expecting a hike of 10% in my current organization.

• My last CTC was INR 8 lakhs per annum.

• I am expecting a hike of 10% in my current organization.

• I am open to negotiation based on the job responsibilities and market standards.

Sales involves identifying customer needs, presenting products or services, and closing deals to generate revenue.

• Understanding customer needs and preferences

• Effective communication and persuasion skills

• Product knowledge and ability to highlight benefits

• Negotiation and closing techniques

• Building and maintaining customer relationships

• Meeting sales targets and goals

SQL joins are used to combine rows from two or more tables based on a related column between them.

• Types of SQL joins include INNER JOIN, LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• INNER JOIN returns rows when there is at least one match in both tables.

• LEFT JOIN returns all rows from the left table and the matched rows from the right table.

• RIGHT JOIN returns all rows from the right table and the matched rows from the left table.

• FULL JOIN returns rows when there is a match in one of ...read more

My expected CTC is in line with industry standards and commensurate with my experience and skills.

• I have researched the market and have a good understanding of the salary range for this position

• I am open to negotiation based on the overall compensation package

• I am looking for a fair and competitive salary that reflects my qualifications and contributions to the company