8000+ Software Engineer Interview Questions and Answers

Generate and print all prime numbers between 2 and N, inclusive.

• Iterate from 2 to N and check if each number is prime

• Use a helper function to determine if a number is prime

• Print each prime number on a new line

Reverse the order of elements in an array and display the reversed array.

• Create a function that takes an array as input

• Use a loop to iterate through the array and swap elements at opposite ends

• Return the reversed array

Given a string and a list of words, determine if each word in the list is present in the string and return a boolean array indicating their presence.

• Iterate through each word in the word list and check if it is present in the string.

• Use a boolean array to store the presence of each word in the string.

• Remember that the presence of a word is case sensitive.

• Do not use built-in string-matching methods.

• Return the boolean array without printing it.

The challenge involves forming dance pairs from available boys and girls based on potential pairings to maximize the number of pairs.

• Parse the input to get the number of test cases, boys, girls, and potential pairings.

• Iterate through the potential pairings and form pairs based on the given indexes.

• Output '1' if a set of maximum possible pairs is returned, else output '0'.

• There can be multiple valid configurations of pairs.

• Example: For input '2 2 2' and pairings '1 1' and '2 2...read more

Merge two sorted arrays into one sorted array in place.

• Iterate from the end of both arrays and compare elements to merge in place

• Use two pointers to keep track of the current position in each array

• Handle cases where one array is fully merged before the other

Reverse a given stack of integers using recursion without using extra space or loops.

• Use recursion to pop all elements from the original stack and store them in function call stack

• Once the stack is empty, push the elements back in reverse order using recursion

• Use the top(), pop(), and push() methods to manipulate the stack

Implement a Sudoku solver to fill empty slots in a 9x9 grid with numbers 1-9 satisfying constraints.

• Create a recursive function to solve the Sudoku puzzle by trying out different numbers in empty slots.

• Use backtracking to backtrack and try a different number if a conflict is encountered.

• Ensure each number appears only once per row, column, and 3x3 grid.

• Return the completed Sudoku grid as the output.

Interview questions for Software Engineer position

• Array manipulation and linked list operations

• Tree data structure and balancing techniques

• Database concepts and differences between SQL and NoSQL

• Web development frameworks and protocols

• Concepts of Deadlock and Race Condition

• Use of pointers in function oriented programming and their absence in Java

Generate all possible valid parentheses configurations with N pairs.

• Use backtracking to generate all possible combinations of parentheses.

• Keep track of the number of open and close parentheses used.

• Add '(' if there are remaining open parentheses, and add ')' if there are remaining close parentheses.

To win the coin placement game, start by placing a coin in the center and mirror your opponent's moves.

• Place your first coin in the center of the table.

• After your opponent places a coin, identify the position relative to the center.

• Reflect their move across the center point to maintain symmetry.

• This strategy ensures that you always have a valid move until the table is full.

Find the maximum difference between any two elements in an array and determine if it is even or odd.

• Iterate through the array to find the maximum and minimum elements.

• Calculate the difference between the maximum and minimum elements.

• Check if the difference is even or odd and return the result.

Minimum number of airplanes needed to get one airplane all the way around the world and return safely to the airport.

• To achieve this, we need 3 airplanes in total.

• The first airplane flies halfway around the world, then transfers half of its fuel to the second airplane.

• The first airplane then returns to the airport, while the second airplane continues to fly the remaining half of the journey.

• When the second airplane reaches the destination, it transfers all its fuel to the thi...read more

Given a railway seat number, determine if it is valid and identify its berth type.

• Parse input integer 't' for number of test cases

• For each test case, check if seat number is valid (1 <= N <= 100)

• Identify berth type based on seat number and output the result

• Possible berth types are Lower, Middle, Upper, Side Lower, and Side Upper

The task is to determine the total number of ways to make change for a specified value using given denominations.

• Create a dynamic programming table to store the number of ways to make change for each value up to the target value.

• Iterate through each denomination and update the table accordingly based on the current denomination.

• The final value in the table will represent the total number of ways to make change for the target value.

• Consider edge cases such as when the target v...read more

The task is to determine the minimum number of platforms needed at a railway station based on arrival and departure times of trains.

• Sort the arrival and departure times in ascending order.

• Use two pointers to track overlapping schedules.

• Increment platform count when a new train arrives before the previous one departs.

Validate if a given string is a palindrome after removing special characters, spaces, and converting to lowercase.

• Remove special characters and spaces from the input string

• Convert the string to lowercase

• Check if the modified string is equal to its reverse to determine if it's a palindrome

Develop an algorithm to compress a string by replacing consecutive duplicate characters with the character followed by the count of its repetitions.

• Iterate through the input string while keeping track of consecutive character counts.

• Replace consecutive duplicate characters with the character followed by the count if count exceeds 1.

• Ensure the count does not exceed 9 for each character.

• Return the compressed string as output.

Program for Fibonacci series for n terms with user input.

• Take user input for n

• Initialize variables for first two terms of Fibonacci series

• Use a loop to generate the series up to n terms

• Print the series

I will troubleshoot the router by checking the power supply, resetting the router, and checking the network settings.

• Check if the router is properly plugged in and receiving power

• Reset the router by turning it off and on again

• Check the network settings and make sure they are correct

• Try connecting to the router with a different device

• If all else fails, contact the internet service provider for assistance

Maximum distance that can be traveled using 3 wheels, each with a 5km limit and requiring 2 wheels to move forward.

• Using all 3 wheels, we can move forward a total of 10kms (5kms using 2 wheels at a time)

• After using the first 2 wheels to travel 5kms, we can switch to the remaining wheel and travel another 5kms

• Alternatively, we can use 2 wheels to travel 5kms, then switch to the remaining wheel and use another 2 wheels to travel another 5kms, for a total of 10kms

A compiler translates the entire program into machine code before execution, while an interpreter translates and executes the program line by line.

• A compiler converts the source code into an executable file, while an interpreter executes the code directly.

• Compilers typically produce faster and more efficient code, while interpreters provide faster development and debugging.

• Examples of compilers include GCC, Clang, and Visual C++, while examples of interpreters include Python,...read more

The task is to determine the frequency of each character from 'a' to 'z' in a given string.

• Create an array of size 26 to store the frequency of each character from 'a' to 'z'.

• Iterate through the input string and increment the corresponding index in the array for each character encountered.

• Output the array of frequencies for each test case.

Find the length of longest substring composed of same digit within a string of digits.

• Iterate through the string and keep track of the current digit and its count

• Update the maximum count whenever a new digit is encountered

• Return the maximum count

Find the greatest common divisor (GCD) of two given numbers 'X' and 'Y'.

• Implement a function to calculate the GCD of two numbers using Euclidean algorithm

• Iteratively find the remainder of dividing the larger number by the smaller number until the remainder is 0

• The last non-zero remainder is the GCD of the two numbers

4 people with different crossing times need to cross a bridge with one torch. Only 2 can cross at a time. What's the minimum time?

• The person with the longest time should always be accompanied by someone else

• The two fastest people should cross together to save time

• The torch needs to be brought back to the starting side every time two people cross

• The total time taken will be the sum of all individual crossing times

Modify a boolean matrix such that if any element is 1, set its entire row and column to 1.

• Iterate through the matrix and mark rows and columns to be modified

• Use additional arrays to keep track of rows and columns to be modified

• Update the matrix in-place based on the marked rows and columns

Algorithm to find if a number is present in a sorted n x n matrix with linear time complexity.

• Start with the top right element

• Compare the element with x

• If equal, return its position

• If e < x, move down (if out of bounds, return false)

• If e > x, move left (if out of bounds, return false)

• Repeat till element is found or returned false