4500+ Senior Software Engineer Interview Questions and Answers

The task is to find the Nth prime number given a number N.

• A prime number is a number greater than 1 that is not a product of two smaller natural numbers.

• Prime numbers have only two factors - 1 and the number itself.

• Start with a counter at 0 and a number at 2.

• Increment the number by 1 and check if it is prime.

• If it is prime, increment the counter.

• Repeat until the counter reaches N.

• Return the last prime number found.

The interview questions cover a wide range of topics including software engineering, technology, design patterns, databases, web development, and more.

• The questions cover topics such as technology used, collections, streams, design patterns, dependency injection, microservices, database communication, annotations in Spring, React and JavaScript, Redux, API development, SOAP-based web services, Jenkins, Docker, production support, and more.

• Some specific questions include the d...read more

Given an unsorted array, find the K largest elements in non-decreasing order.

• Sort the array in non-decreasing order.

• Return the last K elements of the sorted array.

The question asks to implement a data structure called 'MapSum' with functions to initialize, insert key-value pairs, and find the sum of values with a given prefix.

• Implement a class called 'MapSum' with a constructor to initialize the data structure.

• Implement the 'insert' function to insert key-value pairs into the 'MapSum'. If a key is already present, replace its value with the new one.

• Implement the 'sum' function to find the sum of values whose key has a prefix equal to t...read more

Generate Pascal's triangle up to the Nth row using a 2-D list.

• Iterate through each row up to N, starting with [1] as the first row.

• Calculate each element in a row by summing the two elements directly above from the previous row.

• Append each row to the 2-D list until reaching the Nth row.

• Example: For N = 4, the output would be [ [1], [1, 1], [1, 2, 1], [1, 3, 3, 1] ]

SOLID principles ensure maintainable and scalable code. Dependency Injection helps in achieving loose coupling and testability.

• SOLID principles are Single Responsibility, Open-Closed, Liskov Substitution, Interface Segregation, and Dependency Inversion

• Dependency Injection is a design pattern that allows objects to be loosely coupled and easily testable

• Use Dependency Injection to reduce tight coupling between classes and make them more modular

• Use SOLID principles to ensure mai...read more

The task is to determine the maximum profit that can be achieved by performing up to two buy-and-sell transactions on a given set of stock prices.

• Iterate through the array of stock prices to find the maximum profit that can be achieved by buying and selling stocks at different points.

• Keep track of the maximum profit that can be achieved by considering all possible combinations of buy and sell transactions.

• Ensure that you sell the stock before you can buy again to adhere to th...read more

The task is to reverse a given string containing alphanumeric and special characters.

• Iterate through the string from the last character to the first character

• Append each character to a new string to get the reversed string

• Return the reversed string as the output

The problem involves decoding a numeric sequence into a valid string using a given mapping of characters to numbers.

• Use dynamic programming to count the number of ways to decode the sequence.

• Consider different cases for decoding single digits and pairs of digits.

• Keep track of the number of ways to decode at each position in the sequence.

• Return the final count modulo 10^9 + 7 as the answer.

Convert Excel column title to corresponding column number.

• Iterate through the characters in the input string from right to left

• Calculate the corresponding value of each character based on its position and multiply by 26^position

• Sum up all the values to get the final column number

Given a string STR and a non-empty string PTR, find all starting indices of anagrams of PTR within STR.

• Create a frequency map of characters in PTR.

• Use sliding window technique to check anagrams in STR.

• Return the starting indices of anagrams found.

Design a Least Recently Used (LRU) cache data structure that supports get and put operations with capacity constraint.

• Implement a doubly linked list to keep track of the order of keys based on their recent usage.

• Use a hashmap to store key-value pairs for quick access and updates.

• When capacity is reached, evict the least recently used item before inserting a new item.

• Update the order of keys in the linked list whenever a key is accessed or updated.

Given an integer, find the final single-digit value after summing its digits iteratively.

• Iteratively sum the digits of the input integer until the result is a single-digit number

• Output the final single-digit integer for each test case

• Handle multiple test cases as input

The task is to identify all distinct triplets within an array that sum up to a specified number.

• Iterate through the array and use nested loops to find all possible triplets.

• Keep track of the sum of each triplet and compare it with the target sum.

• Print the triplet if the sum matches the target sum, else print -1.

Return the boundary nodes of a binary tree in Anti-Clockwise direction starting from the root node.

• Traverse the left boundary nodes in top-down order

• Traverse the leaf nodes in left-right order

• Traverse the right boundary nodes in bottom-up order

• Handle cases where duplicates occur in boundary nodes

Count the number of ways to reach target from source in a grid with 0s and 1s.

• Use dynamic programming to solve the problem efficiently.

• Traverse the grid using DFS or BFS to count the number of ways.

• Consider edge cases like when source and target are the same or when there is no path.

• Example: Given grid = [[0,0,0],[0,1,0],[0,0,0]], source = (0,0), target = (2,2), answer is 2.

• Example: Given grid = [[0,1],[0,0]], source = (0,0), target = (1,1), answer is 1.

Create a program to count lowercase alphabets, digits, and white spaces from user input until '$' is encountered.

• Read characters from input stream until '$' is encountered

• Count lowercase alphabets, digits, and white spaces separately

• Print the counts of each character type as three integers separated by spaces

The problem involves decoding a numeric sequence back into a valid string based on a given mapping of characters to numeric values.

• Use dynamic programming to keep track of the number of ways to decode the sequence at each position.

• Consider edge cases such as '0' and '00' which do not have valid decodings.

• Handle cases where two digits can be combined to form a valid character (e.g., '12' corresponds to 'L').

Calculate the number of bit flips required to convert one number to another in binary representation.

• Convert both numbers to binary representation

• Count the number of differing bits between the two numbers

• Output the count of differing bits as the number of bit flips required

• Example: A = 13 (1101), B = 7 (0111) -> 2 bit flips required

Check if a given string is a palindrome considering only alphanumeric characters.

• Remove non-alphanumeric characters from the input string before checking for palindrome.

• Use two pointers approach to compare characters from start and end of the string.

• Convert all characters to lowercase for case-insensitive comparison.

• Return true if the string is a palindrome, false otherwise.

Program to find the Nth term in an infinite series

• The series has a repeating pattern

• Use modulo operator to find the index of the repeating pattern

• Calculate the value of Nth term based on the pattern

Implement a function to find all starting indices of anagram substrings of a given string in another string.

• Create a frequency map of characters in the 'PTR' string.

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

• Return the starting indices of anagram substrings found.

• Example: For input 'BACDGABCD' and 'ABCD', output should be [0, 5].

Find the K-th largest element in a BST.

• Perform reverse in-order traversal of the BST to find the K-th largest element.

• Keep track of the count of visited nodes to determine the K-th largest element.

• Return -1 if there is no K-th largest element in the BST.

The question is about designing and implementing a data structure for LRU cache to support get and put operations.

• LRU cache is a cache replacement policy that removes the least recently used item when the cache reaches its capacity.

• The cache is initialized with a capacity and supports get(key) and put(key, value) operations.

• For each get operation, return the value of the key if it exists in the cache, otherwise return -1.

• For each put operation, insert the value in the cache i...read more

Calculate the total amount of rainwater that can be trapped in given elevation map.

• Iterate through the array to find the maximum height on the left and right of each bar.

• Calculate the amount of water that can be trapped above each bar by taking the minimum of the maximum heights on the left and right.

• Sum up the trapped water above each bar to get the total trapped water for the entire elevation map.

Implement a search function to find a specified integer in a rotated sorted array with O(logN) time complexity.

• Implement a binary search algorithm to efficiently search for the target integer.

• Handle the rotation of the array by finding the pivot point first.

• Return the index of the target integer if found, else return -1.

• Ensure the time complexity of the search function is O(logN) for each query.

The problem involves counting the number of distinct ways to climb N stairs by taking 1 or 2 steps at a time.

• Use dynamic programming to solve this problem efficiently.

• The number of ways to reach the Nth stair is equal to the sum of ways to reach (N-1)th stair and (N-2)th stair.

• Handle modulo 10^9+7 to avoid overflow issues.

• Consider base cases for 0th and 1st stair.

• Optimize the solution by using constant space instead of an array.