1500+ System Engineer Interview Questions and Answers

Determine the winner of an election between two candidates based on the influence of supporters on neutral voters.

• Iterate through the string to count the number of supporters for each candidate.

• Simulate the movement of supporters of A and B to influence neutral voters.

• Compare the total number of supporters for A and B to determine the election winner.

• Handle cases where there is a tie by declaring it as a Coalition.

The problem involves determining the number of distinct ways to climb from the 0th to 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 based on the number of ways to reach the previous two stairs.

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

• Keep track of the number of ways modulo 10^9+7 to avoid overflow issues.

The greatest common divisor (GCD) of two numbers is the largest positive integer that divides both numbers without leaving a remainder.

• Use Euclidean algorithm to find GCD efficiently

• GCD(X, Y) = GCD(Y, X % Y)

• Repeat until Y becomes 0, then X is the GCD

Find the sum of the subarray with the maximum sum among all subarrays in an array of integers.

• Iterate through the array and keep track of the maximum sum subarray encountered so far.

• Use Kadane's algorithm to efficiently find the maximum subarray sum.

• Consider the sum of an empty subarray as 0.

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.

• Consider case sensitivity when checking for word presence.

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

• Return the boolean array without printing it.

The task is to determine if the given string of parentheses is balanced or not.

• Use a stack to keep track of opening parentheses

• When encountering a closing parenthesis, check if it matches the top of the stack

• If the stack is empty or the parentheses do not match, the string is not balanced

• Return 'YES' if all parentheses are balanced, 'NO' otherwise

Find pairs of elements in an array that sum up to a given value, sorted in a specific order.

• Iterate through the array and for each element, check if the complement (S - current element) exists in a hash set.

• If the complement exists, add the pair to the result list.

• Sort the result list based on the criteria mentioned in the question.

• Return the sorted list of pairs.

Check if a given string is identical to its mirror reflection.

• Iterate through the string and compare characters from start and end simultaneously.

• If any characters don't match, return 'NO'.

• If all characters match, return 'YES'.

OOPs concepts are the fundamental principles of Object-Oriented Programming.

• Encapsulation: Binding data and functions together in a single unit.

• Inheritance: Acquiring properties and behavior of a parent class by a child class.

• Polymorphism: Ability of an object to take many forms.

• Abstraction: Hiding the implementation details and showing only the necessary information.

• Example: A car is an object that encapsulates data like speed, fuel, and functions like start, stop, and accel...read more

System Engineer interview questions covering tech stacks, Java, Spring, Hibernate, REST, and API security.

• Tech stacks include Java, Spring, Hibernate, REST, and API security.

• Class loader loads classes into JVM at runtime.

• Auto Configuration automatically configures Spring beans based on classpath and other conditions.

• An object is an instance of a class that has state and behavior.

• Exceptions in Spring can be handled using try-catch blocks or using @ExceptionHandler annotation.

• I...read more

Reverse a singly linked list by altering the links between nodes.

• Iterate through the linked list and reverse the links between nodes

• Use three pointers to keep track of the current, previous, and next nodes

• Update the links while traversing the list to reverse it

• Return the head of the reversed linked list

Detect if a singly linked list forms a cycle by checking if a node's next points back to a previous node.

• Use Floyd's Cycle Detection Algorithm to determine if there is a cycle in the linked list.

• Maintain two pointers, one moving at twice the speed of the other, if they meet at some point, there is a cycle.

• If one of the pointers reaches the end of the list (null), there is no cycle.

The problem involves finding the number of twin pairs in an array based on a specific condition.

• Iterate through the array and check for each pair of indices if they form a twin pair based on the given condition

• Keep track of the count of twin pairs found

• Return the total count of twin pairs for each test case

To achieve NlogN complexity in the worst case, we can implement the randomized version of quicksort algorithm.

• Randomly select a pivot element to reduce the chances of worst-case scenarios.

• Implement a hybrid sorting algorithm like Introsort which switches to heap sort when the recursion depth exceeds a certain limit.

• Use median-of-three partitioning to select a good pivot element for better performance.

• Optimize the algorithm by using insertion sort for small subarrays to reduce...read more

Implement a Trie data structure supporting insertion and search operations for words.

• Create a TrieNode class with a dictionary to store children nodes.

• Implement insert(word) by iterating through each character of the word and creating nodes if necessary.

• Implement search(word) by traversing the Trie and checking for the presence of the word.

• Use a boolean flag in TrieNode to mark the end of a word.

• Handle Type 1 and Type 2 queries accordingly in the main program.

The task is to distribute candies to students based on their performance while minimizing the total candies distributed.

• Create an array to store the minimum candies required for each student.

• Iterate through the students' ratings array to determine the minimum candies needed based on the given criteria.

• Consider the ratings of adjacent students to decide the number of candies to distribute.

• Calculate the total candies required by summing up the values in the array.

• Implement a fu...read more

Implement the merge sort algorithm to sort a singly linked list of integers.

• Divide the linked list into two halves recursively

• Merge the sorted halves using the merge() function

• Implement the merge() function to merge two sorted subarrays

• Ensure the constraints are met for input elements

• Return the sorted linked list for each test case

Implement a function to compress a string by replacing consecutive characters with the character followed by the count of repetitions.

• Iterate through the input string and keep track of consecutive characters and their counts

• Replace consecutive characters with the character followed by the count of repetitions if count is greater than 1

• Return the compressed string

Yes, the 0/1 Knapsack Problem can be solved using dynamic programming with a space complexity of not more than O(W).

• Use a 1D array to store the maximum value that can be stolen for each weight capacity from 0 to W.

• Iterate through each item and update the array based on whether including the item would increase the total value.

• The final element of the array will contain the maximum value that can be stolen within the weight capacity of the knapsack.

Print a binary pattern based on input integer N in a specific format.

• Iterate from N to 1 and print N - i + 1 numbers alternatively as 1 or 0 in each line

• Handle the test cases by reading the number of test cases first

• Follow the given constraints for input and output format

Group anagrams in a list of strings and return them as separate groups.

• Iterate through the list of strings and sort each string to find anagrams.

• Use a hashmap to group anagrams together based on their sorted versions.

• Return the grouped anagrams as separate lists of strings.

The task is to determine the maximum number of unique vehicle registrations given the number of districts, letter ranges, and digit ranges.

• Parse the input for each test case: number of districts, letter ranges, and digit ranges.

• Calculate the total number of unique registrations based on the given constraints.

• Output the maximum number of unique vehicle registrations for each test case.

• Consider the ranges of alphabets and digits to determine the total combinations possible.

• Ensu...read more

The task is to determine the number of distinct islands in a grid of 0s and 1s connected horizontally, vertically, or diagonally.

• Iterate through the grid and for each '1' encountered, perform a depth-first search to mark all connected '1's as visited.

• Use a set to store the unique shapes of islands encountered during the traversal.

• Return the size of the set as the total number of distinct islands in the grid.

Integrity rules in a DBMS ensure data accuracy, consistency, and reliability.

• Constraints like primary key, foreign key, unique key enforce data integrity

• Referential integrity ensures relationships between tables are maintained

• Entity integrity ensures each row has a unique identifier

• Domain integrity enforces valid data types and values

• Check constraints validate data before insertion or update

INNER JOIN returns only the matching rows between two tables, while OUTER JOIN returns all rows from one table and matching rows from the other.

• INNER JOIN is used to retrieve rows from both tables that have matching values based on a specified condition.

• OUTER JOIN is used to retrieve all rows from one table and only matching rows from the other table.

• Types of OUTER JOIN include LEFT JOIN, RIGHT JOIN, and FULL JOIN.

• Example: INNER JOIN would return a list of students who have r...read more

Generate all valid parentheses combinations for a given number of 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.

• Stop when the length of the generated string is equal to 2*N.

Count the total number of unique pairs in an array whose elements sum up to a given value.

• Iterate through the array and for each element, check if the complement (Sum - current element) exists in a hash set.

• If the complement exists, increment the count of pairs and add the current element to the hash set.

• Return the total count of pairs at the end.

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 looted or not.

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

The problem involves maximizing profit by cutting a rod into pieces with different costs associated with each length.

• Iterate through all possible cuts and calculate the maximum profit for each length

• Use dynamic programming to store and reuse subproblem solutions

• Choose the cut that maximizes profit at each step

• Return the maximum profit obtained by selling the pieces

Calculate the minimum cost to connect all points on a 2D plane using Manhattan distance.

• Iterate through all pairs of points and calculate Manhattan distance between them

• Use a minimum spanning tree algorithm like Kruskal's or Prim's to find the minimum cost

• Ensure all points are connected with one simple path only

Determine the maximum time Ninja can survive in a space survival game challenge with different planet effects on health and armour.

• Create a function that takes initial health and armour as input for each test case

• Simulate Ninja's movement between planets and update health and armour accordingly

• Keep track of the maximum time Ninja can survive before health or armour reaches 0

Cut the cake horizontally twice and then vertically once.

• Cut the cake horizontally into two equal halves.

• Stack the two halves and cut horizontally again to get four equal pieces.

• Finally, cut vertically through the center to get eight equal pieces.

The task is to determine if an array can be divided into pairs such that the sum of each pair is divisible by a given integer.

• Iterate through the array and calculate the remainder of each element when divided by K.

• Store the remainders in a hashmap with their frequencies.

• Check if the frequencies of remainders are even and if the sum of each pair of remainders is divisible by K.

The goal is to minimize the difference between the maximum and minimum elements of an array by adjusting each element by a given value.

• Iterate through the array and for each element, calculate the minimum and maximum possible values after adjusting by K

• Find the minimum and maximum values after adjustments for all elements

• Calculate the difference between the maximum and minimum values to get the final result

Remove duplicates from an array of integers while maintaining the order.

• Use a set to keep track of unique elements while iterating through the array.

• Add elements to the set if they are not already present.

• Convert the set back to an array to maintain order.

Constructor is a special method used to initialize an object, while a method is a function that performs a specific task within a class.

• Constructors are called automatically when an object is created, while methods need to be called explicitly.

• Constructors have the same name as the class, while methods have unique names.

• Constructors do not have a return type, while methods can have a return type.

• Example: Constructor - public ClassName() { // initialization code }, Method - pu...read more

SQL is a programming language used to manage and manipulate relational databases.

• SQL stands for Structured Query Language.

• It is used to create, modify, and query databases.

• SQL is used in various industries such as finance, healthcare, and e-commerce.

• Examples of SQL commands include SELECT, INSERT, UPDATE, and DELETE.

• SQL is used to retrieve specific data from a database using queries.

Matlab is a programming language and environment used for numerical computation, data analysis, and visualization.

• Matlab is used for development and testing in various fields such as engineering, finance, and scientific research.

• Some tools commonly used in Matlab development and testing are Simulink, MATLAB Compiler, and MATLAB Coder.

• Matlab supports various data types including numeric, logical, character, and cell arrays.

• Embedded C is a subset of the C programming language u...read more

The relationship between a train's speed passing through a platform and the relative speed of two trains is influenced by their individual speeds and direction.

• The relative speed of two trains passing each other is the sum of their individual speeds in opposite directions.

• When a train passes through a platform, its speed relative to the platform is the difference between its speed and the platform's speed.

• The relative speed of two trains passing through a platform can be calc...read more

Multitasking refers to the ability of an operating system to run multiple tasks concurrently, while multithreading involves executing multiple threads within a single process.

• Multitasking allows multiple programs to run simultaneously on a single processor, switching between them quickly.

• Multithreading enables a single program to perform multiple tasks concurrently by dividing it into smaller threads that can be executed independently.

• Multitasking is at the process level, whi...read more

Check if the binary representation of a given integer is a palindrome.

• Convert the integer to binary representation.

• Check if the binary representation is a palindrome by comparing it with its reverse.

• Return true if it is a palindrome, false otherwise.

Find the position of the first occurrence of '1' in a sorted array of 0's and 1's.

• Iterate through the array and find the index of the first '1'.

• Return the index + 1 as the position (1-based indexing).

• If no '1' is found, return -1.

To select a record from a table, use the SELECT statement with appropriate conditions.

• Use the SELECT statement with the appropriate columns to retrieve data from the table.

• Specify the table name in the FROM clause.

• Use the WHERE clause to specify the conditions for selecting the record.

• Example: SELECT * FROM table_name WHERE column_name = 'value';

Procedural programming focuses on procedures and functions, while OOP emphasizes objects and classes.

• Procedural programming uses a top-down approach, while OOP uses a bottom-up approach.

• In procedural programming, data and functions are separate, while in OOP, they are encapsulated within objects.

• Procedural programming is more suitable for small-scale programs, while OOP is better for large-scale projects.

• C is a procedural programming language, lacking the features of OOP like...read more

List of 15 Linux commands with their functions

• ls - list directory contents

• pwd - print working directory

• cd - change directory

• mkdir - make a new directory

• rm - remove files or directories

• cp - copy files and directories

• mv - move or rename files and directories

• grep - search for patterns in files

• chmod - change file permissions

• ps - display information about running processes

• top - display and update sorted information about processes

• kill - send signals to processes

• tar - create or ext...read more

Find duplicates in an array of integers within a specified range.

• Iterate through the array and keep track of the count of each element using a hashmap.

• Return elements with count greater than 1 as duplicates.

• Time complexity can be optimized to O(N) using a set to store duplicates.

A constructor is a special method used to initialize an object, while a method is a function that performs a specific task.

• Constructors are called automatically when an object is created, while methods need to be called explicitly.

• Constructors have the same name as the class, while methods can have any valid name.

• Constructors do not have a return type, while methods can have a return type.

• Constructors are used to set initial values of instance variables, while methods are use...read more