500+ Application Developer Interview Questions and Answers

The last ball that will be left is black.

• When you take out 2 black balls, you take another white ball.

• If you take 2 white balls, you take out 1 black ball.

• If balls are of different color, you take out another black ball.

• Since there are more black balls initially, the last ball will be black.

Design a website similar to bookmyshow.com for booking cinema tickets for a single location with multiple theatres.

• Design a user-friendly GUI with options for advance booking, user login, user registration, movie rating, and saving card details.

• Create relevant database tables to store information about movies, theatres, bookings, user details, and card details.

• Link the GUI to the database to enable data flow and retrieval.

• Implement features like advance booking, where users c...read more

A database for managing songs on Spotify playlists.

• Create a table for playlists with columns for name, description, and user ID

• Create a table for songs with columns for title, artist, album, and duration

• Create a table for playlist-songs with columns for playlist ID and song ID

• Use foreign keys to link tables together

• Allow for CRUD operations on playlists and songs

Update Dashboard/Homepage when there is a DB update

• Use a backend service to monitor the DB for updates

• When an update is detected, fetch the updated data from the DB

• Update the Dashboard/Homepage with the new data using a frontend framework like React or Angular

The program prints the substring after a specified character has occurred a certain number of times in a given string.

• Iterate through the string to find the specified character.

• Keep track of the count of occurrences of the character.

• Once the count reaches the specified count, extract the substring after that position.

• Handle corner cases such as when the character is not in the string or when it doesn't occur the specified number of times.

To efficiently manage room bookings and prebookings in a hotel, a priority queue data structure can be implemented.

• A priority queue can be used to prioritize room bookings based on check-in dates.

• When a customer checks out, the room becomes available and can be assigned to the next customer in the priority queue.

• Prebookings can be stored separately and checked against the availability of rooms before assigning them to customers.

• The priority queue can be implemented using a bi...read more

Ansible playbooks automate configuration management. CI/CD pipeline automates software delivery. Tools include Jenkins, GitLab, and Travis CI.

• Ansible playbooks are written in YAML format and define tasks to be executed on remote hosts.

• CI/CD pipeline automates the software delivery process from code commit to production deployment.

• Tools for pipeline creation include Jenkins, GitLab, Travis CI, and CircleCI.

• Pipeline creation involves defining stages, jobs, and triggers to autom...read more

tmap is used to transform data in Talend, tjoin is used to join data. There are different types of connections, truncate and delete are different ways to remove data from a table. ETL stands for Extract, Transform, Load. Triggers are database objects that are automatically executed in response to certain events. There are different types of joins.

• tmap is used for data transformation in Talend

• tjoin is used for joining data in Talend

• Types of connections include database connect...read more

Minimum number of times to turn all glasses upside down when 4 can be turned at a time.

• Turn over any four glasses, leaving one untouched.

• Repeat the above step until only one glass is left upside down.

• Finally, turn over the last glass to complete the task.

• Minimum number of turns required is 3.

Minimum 7 races required to find the top 3 fastest horses.

• Divide the 25 horses into 5 groups of 5 horses each.

• Conduct a race among the horses in each group to determine the fastest horse in each group.

• Take the top 2 horses from each group and conduct a race among them to determine the fastest horse overall.

• The winner of this race is the fastest horse.

• Now, take the second-place horse from the final race and the second-place horse from each group race.

• Conduct a race among these...read more

Create an array of song titles sorted by year of publication.

• Create an array of song objects with properties for title and year of publication.

• Sort the array by year of publication.

• Extract the titles of the songs into a separate array.

• Return the array of song titles.

Print all possible paths from start to end in a linear way, moving either one or two steps right.

• Use dynamic programming to solve the problem

• Create a 2D array to store the number of paths to each position

• Start from the end position and work backwards

• At each position, calculate the number of paths by summing the number of paths from the next two positions

• Print all the paths by backtracking from the start position

The minimum number of races required to find the top 3 among 25 horses is 7.

• Divide the 25 horses into 5 groups of 5 horses each.

• Race the 5 groups, which will give us the top 3 horses from each group.

• Now we have 15 horses remaining.

• Race the top 3 horses from each group, which will give us the top 3 horses overall.

• This requires a total of 7 races.

It depends on the use case. QuickSort is generally the fastest, but MergeSort is more stable and efficient for larger datasets.

• QuickSort is generally the fastest sorting algorithm, but can be unstable for certain datasets.

• MergeSort is more stable and efficient for larger datasets, but can be slower than QuickSort for smaller datasets.

• InsertionSort is efficient for small datasets, but can be slow for larger datasets.

• HeapSort is efficient for larger datasets, but can be slower ...read more

The words in a string can be arranged based on their order of occurrence.

• Split the string into an array of words

• Create a dictionary to store the count of each word

• Sort the array based on the count of each word

• Join the sorted array back into a string

Probability of a stone thrown in a circle with radius r lying near the center.

• The probability of the stone lying near the center is directly proportional to the area of the circle near the center.

• The area of the circle near the center is proportional to the square of the radius.

• Therefore, the probability of the stone lying near the center is proportional to the square of the radius.

• The probability can be calculated by dividing the area of the circle near the center by the tot...read more