8000+ Software Engineer Interview Questions and Answers

To debug the slow behavior of the API, analyze network latency, check for database issues, monitor server performance, and review code for potential bottlenecks.

• Analyze network latency to identify any issues with data transmission.

• Check for database issues such as slow queries or insufficient indexing.

• Monitor server performance to ensure it has enough resources and is not overloaded.

• Review the code for potential bottlenecks, such as inefficient algorithms or excessive databas...read more

Determine the maximum amount of money a thief can steal from houses without looting two consecutive houses.

• Create an array 'dp' to store the maximum money that can be stolen up to the i-th house.

• Iterate through the houses and update 'dp' based on whether the current house is stolen or not.

• Return the maximum value in 'dp' as the answer.

• Example: For input N=4 and values=[6, 7, 1, 30], the output should be 36.

Generate all binary strings of length 'K' with no consecutive '1's in lexicographically increasing order.

• Use backtracking to generate all possible binary strings without consecutive '1's.

• Start with an empty string and recursively add '0' or '1' based on the condition.

• Keep track of the current string and its length to ensure no consecutive '1's are added.

• Sort the generated strings in lexicographically increasing order before outputting.

Merge two sorted linked lists into a single sorted linked list with constant space complexity and linear time complexity.

• Create a dummy node to start the merged list

• Compare the values of the two linked lists and append the smaller value to the merged list

• Move the pointer of the merged list and the pointer of the smaller value's linked list

• Continue this process until one of the linked lists is fully traversed

• Append the remaining elements of the other linked list to the merged ...read more

Check if a given array contains a valid triplet where two elements sum up to the third.

• Iterate through all possible triplets in the array and check if any of the conditions are satisfied.

• Use nested loops to compare each element with every other element in the array.

• Handle cases where the elements are not distinct by ensuring i != j, j != k, and i != k.

The problem is to find the number of ways to form a group of people such that the overall happiness of the group falls within a given range.

• Iterate through all possible subsets of the given array/list

• Calculate the sum of happiness values for each subset

• Count the number of subsets whose sum falls within the given range

Merge overlapping intervals and return sorted list of merged intervals.

• Identify overlapping intervals based on start and end times

• Merge overlapping intervals to form new intervals

• Sort the merged intervals in ascending order of start times

The task is to find the second largest element in an array of integers.

• Iterate through the array and keep track of the largest and second largest elements.

• Initialize the largest and second largest variables with the first two elements of the array.

• Compare each element with the largest and second largest variables and update them accordingly.

• Return the second largest element at the end.

• Handle the case where no second largest element exists.

Check if a given matrix is idempotent by verifying if M * M equals M.

• Calculate the product of the matrix with itself and compare it with the original matrix.

• If the product equals the original matrix, then it is idempotent.

• Iterate through the matrix elements to perform the necessary calculations.

To make the red fishes 98%, 50 fishes have to be removed from the aquarium.

• Calculate 1% of 200 fishes to find out how many fishes represent 1%.

• Multiply the result by 2 to find out how many fishes represent 2%.

• Subtract the result from 200 to find out how many fishes represent 98%.

Given two arrays of strings, find and return the common elements in the order they appear in the second array.

• Iterate through the strings in the second array and check if they exist in the first array.

• Maintain a set to keep track of common elements to avoid duplicates.

• Return the common elements as a single space-separated string in the order they appear in the second array.

Implement Merge Sort algorithm to sort a sequence of numbers in non-descending order.

• Use Divide and Conquer approach to recursively divide the input array into two halves.

• Merge the sorted halves to produce a completely sorted array.

• Ensure the time complexity is O(n log n) for sorting.

• Handle edge cases like empty array, single element array, etc.

Calculate the Nth Fibonacci number efficiently using dynamic programming.

• Use dynamic programming to store previously calculated Fibonacci numbers to avoid redundant calculations.

• Start with base cases F(1) and F(2) as 1, then iterate to calculate subsequent Fibonacci numbers.

• Return the Nth Fibonacci number as the final result.

The question is about calculating the number of distinct ways to reach the Nth stair by climbing one or two steps at a time.

• Use dynamic programming to solve this problem efficiently.

• Define a recursive function to calculate the number of ways to reach each stair.

• Consider base cases for 0 and 1 stairs.

• Use memoization to store intermediate results and avoid redundant calculations.

• Handle large values of N by taking modulo 10^9+7 of the final result.

• Example: For N = 3, the number ...read more

Given constraints and rules, maximize vaccines administered on a specific day during a vaccination drive.

• Iterate through each test case and calculate the maximum number of vaccines administered on the specified day.

• Distribute the available vaccines evenly across the days while adhering to the rules.

• Ensure that the sum of vaccines administered does not exceed the maximum allowed.

• Maximize the vaccines administered on the specified day to meet the requirements.

Count the number of consonants in a given string containing uppercase and lowercase characters and spaces.

• Iterate through each character in the string and check if it is a consonant (not a vowel).

• Keep a count of the consonants encountered while iterating through the string.

• Return the total count of consonants at the end.

Detect cycle in an undirected graph by checking for a path that begins and ends at the same vertex.

• Use Depth First Search (DFS) to traverse the graph and detect cycles.

• Maintain a visited set to keep track of visited vertices and a parent pointer to avoid visiting the same vertex twice.

• If a visited vertex is encountered that is not the parent of the current vertex, a cycle is detected.

• Return 'Yes' if a cycle is found, 'No' otherwise.

Find the row with the maximum number of 1's in a sorted 2D matrix.

• Iterate through each row of the matrix and count the number of 1's in each row.

• Keep track of the row index with the maximum number of 1's seen so far.

• Return the index of the row with the maximum number of 1's.

• If multiple rows have the same number of 1's, return the row with the smallest index.

The task is to find the length of the longest common subsequence between two given strings.

• Use dynamic programming to solve this problem efficiently.

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

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

• Example: For strings 'abcde' and 'ace', the longest common subsequence is 'ace' with length 3.

Merge K sorted arrays into a single sorted array.

• Iterate through all arrays and merge them into a single array.

• Use a min heap to efficiently merge the arrays.

• Implement a custom comparator function for the min heap.

• Time complexity can be optimized to O(N log K) using min heap.

Reverse words in a string word by word, removing leading/trailing spaces and extra spaces between words.

• Split the input string by spaces to get individual words

• Reverse the order of the words

• Join the reversed words with a single space in between

Scheduling is the process of allocating resources to tasks based on priority and availability.

• Different types of scheduling include: preemptive and non-preemptive scheduling, round-robin scheduling, priority scheduling, and deadline scheduling.

• Preemptive scheduling allows higher priority tasks to interrupt lower priority tasks, while non-preemptive scheduling does not.

• Round-robin scheduling allocates a fixed time slice to each task in a cyclic manner.

• Priority scheduling assig...read more

Given a string of '*' and '#', find the maximum number of '*' or '#' to make it a valid string with equal count of both.

• Count the number of '*' and '#' in the string

• Return the minimum count of '*' and '#' as the maximum valid count

• If the count of '*' and '#' is already equal, return that count as the maximum valid count

Find the index of the first occurrence of string A in string B.

• Iterate through string B and check if a substring of length equal to A matches A.

• Return the index of the first occurrence of A in B, or -1 if not found.

Generate and print all possible permutations of a given input string.

• Use recursion to generate all permutations by swapping characters in the string.

• Maintain a visited array to keep track of characters already used in a particular permutation.

• Print each permutation as it is generated.

• Handle duplicate characters by skipping swapping if the character is already in the current position.

Reverse a given string containing characters from [a-z], [A-Z], [0-9], and special characters.

• Iterate through the characters of the string from end to start and append them to a new string to get the reversed string.

• Use built-in functions like reverse() or StringBuilder in languages like Java for efficient reversal.

• Handle special characters and numbers along with alphabets while reversing the string.

• Ensure to print each reversed string on a separate line as per the output for...read more

Identify all prime numbers less than or equal to a given positive integer N.

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

• Use the Sieve of Eratosthenes algorithm for efficient prime number identification

• Optimize by only checking up to the square root of N for divisors