100+ Sdet Interview Questions and Answers

Given a 2D array of alphabets and a function to check valid English words, find all possible valid words adjacent to each other.

• Create a recursive function to traverse the 2D array and check for valid words

• Use memoization to avoid redundant checks

• Consider edge cases such as words with repeating letters

• Optimize the algorithm for time and space complexity

The program takes a string as input and capitalizes the first letter of each reversed word while keeping the rest of the letters in lowercase.

• Split the input string into an array of words using the space as a delimiter

• Iterate through each word in the array

• Reverse the word and capitalize the first letter

• Join the modified words back into a single string with spaces in between

When entering a URL and hitting enter, the browser performs DNS lookup, establishes a TCP connection, sends an HTTP request, receives the response, and renders the page.

• Browser performs DNS lookup to resolve the domain name to an IP address

• Browser establishes a TCP connection with the server

• Browser sends an HTTP request to the server

• Server processes the request and sends back an HTTP response

• Browser receives the response and starts rendering the page

Insert a node at its correct position in a circular linked list containing sorted elements.

• Traverse the linked list until the correct position is found

• Handle the case where the value to be inserted is smaller than the smallest element or larger than the largest element

• Update the pointers of the neighboring nodes to insert the new node

• Consider the case where the linked list has only one node

To check if each page of Amazon.com has its logo, we can use automated testing with Selenium WebDriver.

• Use Selenium WebDriver to navigate to each page of Amazon.com

• Locate the logo element on each page using its XPath or CSS selector

• Verify that the logo element is displayed on each page

Maximize clothes donation between two sets of countries with one-to-one relationships.

• Identify countries in set 1 and set 2.

• Create a graph where edges represent donations between countries.

• Use a maximum bipartite matching algorithm (e.g., Hopcroft-Karp) to find optimal pairs.

• Calculate total donations based on matched pairs.

• Example: If country A donates to country B, ensure A doesn't donate to another country.

To design a search engine with keyword-based document indexing and numeric attributes, we need to build appropriate indices.

• Create an inverted index for each keyword, mapping it to the documents that contain it

• For numeric attributes, use a B-tree or other appropriate data structure to store the values and their associated documents

• Combine the indices to allow for complex queries, such as keyword and attribute filters

• Consider using stemming or other text processing techniques ...read more

Design a data structure to efficiently manage and delete expired web pages without references.

• Use a hash table to store active pages with their URLs as keys for quick access.

• Implement a linked list to maintain the order of pages for easy deletion of expired pages.

• Utilize a timestamp to track the last access time of each page, allowing for easy identification of expired pages.

• Consider a garbage collection mechanism that periodically scans for and removes pages with no referenc...read more

Implement spelling and word suggestions for full keyboard phones

• Create a dictionary of commonly used words

• Use algorithms like Trie or Levenshtein distance to suggest words

• Implement auto-correct feature

Testing Google Analytics involves validating data accuracy, user interface, performance, and integration with other tools.

• Verify data accuracy by comparing reported metrics with raw data from the source.

• Test user interface for usability and accessibility, ensuring all elements are intuitive.

• Conduct performance testing to ensure the application can handle high traffic without degradation.

• Check integration with other tools (e.g., Google Ads) to ensure data flows correctly betwe...read more

Yes, I have worked on automation frameworks.

• I have experience in developing and maintaining automation frameworks using tools like Selenium, TestNG, and Cucumber.

• I have also worked on customizing existing frameworks to meet specific project requirements.

• I am familiar with both data-driven and keyword-driven frameworks.

• I have integrated automation frameworks with CI/CD pipelines for continuous testing.

• One example of a project where I worked on an automation framework was for a...read more

To check if a string is a palindrome, compare the first and last characters, then move towards the center.

• Remove all non-alphanumeric characters and convert to lowercase

• Use two pointers, one starting from the beginning and the other from the end

• Compare the characters at both pointers, move towards the center until they meet

• If all characters match, the string is a palindrome

Calculate the frequency of each grade from a student table and sort it in descending order.

• Use SQL query: SELECT grade, COUNT(*) as frequency FROM students GROUP BY grade ORDER BY frequency DESC.

• Example table: | Name | Grade | |-------|-------| | Alice | A | | Bob | B | | Carol | A |

• Resulting output: | Grade | Frequency | |-------|-----------| | A | 2 | | B | 1 |

To find a given integer in a circularly sorted array of integers.

• Find the pivot point where the array is rotated

• Perform binary search on the two sorted subarrays

• Return the index of the found integer

Parallel execution of test cases in TestNG can be achieved using TestNG's parallel attribute in the testng.xml file.

• Set the 'parallel' attribute in the testng.xml file to 'methods', 'classes', or 'tests' to specify the level of parallelism.

• Use the 'thread-count' attribute to specify the number of threads to be used for parallel execution.

• Ensure that the test classes are thread-safe to avoid any conflicts during parallel execution.

Test cases for a web page with a browse button and an image holder.

• Verify that the browse button is displayed on the page.

• Check that the image holder is empty before any image is uploaded.

• Test uploading a valid image file and ensure it appears in the image holder.

• Attempt to upload an invalid file type (e.g., .txt) and verify an error message is shown.

• Ensure that the image holder can display various image formats (e.g., .jpg, .png).

• Check the maximum file size limit for uploads...read more

Test cases for API creating User's profile with First name, Last name, and mobile number

• Verify that a user profile is created successfully with valid First name, Last name, and mobile number

• Test with invalid First name (empty, special characters, numbers)

• Test with invalid Last name (empty, special characters, numbers)

• Test with invalid mobile number (empty, alphabets, special characters, less than 10 digits)

• Verify that duplicate profiles are not created for the same mobile num...read more

Use a hash map to index anagrams by sorting characters as keys.

• Create a hash map where the key is the sorted string of characters.

• For example, 'top' and 'pot' both map to 'opt'.

• Store all anagrams in a list associated with the sorted key.

• When querying, sort the input word and retrieve the list from the map.

Reverse every 3 nodes in a singly linked list using recursion.

• Create a recursive method that takes the head of the linked list as input.

• If the head is null or there are less than 3 nodes remaining, return the head.

• Reverse the first 3 nodes by swapping their pointers.

• Recursively call the method on the next 3 nodes and update the pointers accordingly.

• Return the new head of the reversed linked list.

To determine if someone has won a game of tic-tac-toe on a board of any size, we need to check all possible winning combinations.

• Create a function to check all rows, columns, and diagonals for a winning combination

• Loop through the board and call the function for each row, column, and diagonal

• If a winning combination is found, return the player who won

• If no winning combination is found and the board is full, return 'Tie'

• If no winning combination is found and the board is not f...read more

500 Internal Server Error is a generic error message indicating a problem with the server.

• Server misconfiguration

• Server overload

• Programming errors in server-side code

• Database connection issues

• Insufficient server resources

Design an algorithm for a mobile contact search application that enhances user experience and efficiency.

• Utilize a trie data structure for efficient prefix searching of contact names.

• Implement fuzzy search to handle typos or partial matches, e.g., searching 'Jon' returns 'John'.

• Incorporate filters for sorting results by frequency of contact usage or recent interactions.

• Allow voice search functionality for hands-free access, e.g., 'Call Mom'.

• Provide suggestions based on user b...read more

Program to find intersection of words in two files

• Read both files and store words in two arrays

• Loop through one array and check if word exists in other array

• Print the common words

Find the maximum subsequent distinct and contiguous subarray in a character array.

• Use a sliding window approach to iterate through the array.

• Keep track of the distinct characters in the current subarray.

• Update the maximum length and subarray as necessary.

To find if two linked lists intersect, traverse both lists and compare their tail nodes.

• Traverse both linked lists and find their lengths

• If the lengths are different, move the longer list's head pointer to the difference in length

• Now traverse both lists and compare their nodes until a common node is found

• If no common node is found, the lists do not intersect

Program to reverse words in a string

• Split the input string into an array of words

• Reverse the array of words

• Join the reversed array back into a string

Facebook's database design focuses on scalability, user relationships, and efficient data retrieval.

• User Profiles: Each user has a unique profile containing personal information, posts, and friend connections.

• Social Graph: A graph database structure to represent relationships between users, allowing for efficient querying of friends and connections.

• Posts and Interactions: Tables for storing posts, likes, comments, and shares, enabling quick access to user-generated content.

• Ne...read more