100+ Software Engineer Intern Interview Questions and Answers

The problem is to connect N ropes of different lengths into one rope with minimum cost.

• Sort the array of rope lengths in ascending order.

• Initialize a variable to keep track of the total cost.

• While there are more than one rope remaining, take the two shortest ropes and connect them.

• Add the cost of connecting the two ropes to the total cost.

• Replace the two shortest ropes with the connected rope.

• Repeat the above steps until only one rope remains.

• Return the total cost.

The task is to modify a given matrix such that if any element in a row or column is 0, then make all elements in that row and column 0.

• Iterate through the matrix and keep track of rows and columns that contain 0s

• After the first iteration, iterate through the tracked rows and columns and set all elements to 0

• Handle the case where the first row or column contains 0 separately

• To solve with O(1) space complexity, use the first row and first column of the matrix to track the rows ...read more

The task is to determine if two strings are similar based on the given conditions.

• Check if the strings are equal, if yes, return 1

• Divide both strings into two parts and check if any combination satisfies the similarity condition

• If none of the conditions hold true, return 0

The maximum sum from root to leaf in a binary tree, where only parent or child can be included in the sum.

• Use a recursive approach to traverse the binary tree.

• At each node, calculate the maximum sum from its left and right child.

• Compare the sums and return the maximum sum plus the value of the current node.

• Repeat this process until reaching a leaf node.

• Track the maximum sum encountered during the traversal.

The best sorting algorithm is QuickSort due to its average case time complexity of O(nlogn) and low memory usage.

• QuickSort is a divide and conquer algorithm that recursively partitions the array into smaller subarrays and sorts them.

• It has an average case time complexity of O(nlogn) and a worst case time complexity of O(n^2).

• QuickSort has low memory usage as it sorts the array in place, without requiring additional memory.

• It is widely used in practice due to its efficiency an...read more

Waterfall model is a linear sequential approach to software development.

• Phases: Requirements gathering, Design, Implementation, Testing, Deployment, Maintenance

• Each phase must be completed before moving to the next

• No going back to previous phases

• Documentation is important

• Less flexible than Agile model

Psuedo code output and technical MCQs for Software Engineer Intern position

• Provide examples for technical MCQs

• Psuedo code output needs to be calculated

• Assess candidate's technical knowledge

Program to print all Prime Numbers up to the input number using Prime Sieve Algorithm.

• Create a boolean array of size n+1 and initialize all values as true.

• Loop through the array starting from 2 and mark all multiples of each prime number as false.

• Print all the numbers that are still marked as true in the array.

Minimum weight to reach bottom right corner in matrix starting from top left. You can move only down and right.

• Use dynamic programming to solve the problem efficiently

• Create a 2D array to store the minimum weight to reach each cell

• The minimum weight to reach a cell is the minimum of the weight to reach the cell above and the cell to the left plus the weight of the current cell

• The minimum weight to reach the bottom right corner is the value in the last cell of the 2D array

The 4 pillars of object oriented programming are encapsulation, inheritance, polymorphism, and abstraction.

• Encapsulation: Bundling data and methods that operate on the data into a single unit.

• Inheritance: Creating new classes based on existing classes, allowing for code reuse.

• Polymorphism: The ability for objects of different classes to respond to the same message.

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

Find the nearest index of a character in a string for each index.

• Create an array of strings to store the results.

• Loop through each character in the string.

• For each character, loop through the rest of the string to find the nearest index of the same character.

• Store the result in the array.

Test cases are scenarios designed to test software functionality. Bugs are defects in software. Regression testing is retesting after changes.

• Test cases are written to ensure that software meets requirements and functions as expected.

• Bugs are defects or errors in software that cause it to behave unexpectedly or not as intended.

• Regression testing is the process of retesting software after changes have been made to ensure that existing functionality has not been affected.

• Regres...read more

OOPs pillars are Abstraction, Encapsulation, Inheritance, and Polymorphism.

• Abstraction: Hides complex implementation details and only shows necessary features. Example: Car dashboard displaying speed without showing internal engine details.

• Encapsulation: Bundling data and methods that operate on the data into a single unit. Example: Class in Java encapsulates data members and member functions.

• Inheritance: Allows a new class to inherit properties and behavior of an existing cl...read more

Sorting algorithms have different time complexities based on their implementation and efficiency.

• Bubble Sort: O(n^2) - compares adjacent elements and swaps them if they are in the wrong order.

• Merge Sort: O(n log n) - divides the array into two halves, sorts them, and then merges them.

• Quick Sort: O(n log n) - picks a pivot element and partitions the array around the pivot.

• Heap Sort: O(n log n) - builds a max heap and repeatedly extracts the maximum element.

• Insertion Sort: O(n^...read more

Remove first and last repeating number from the list without using any space complexity.

• Iterate through the list and keep track of the first and last occurrences of each number.

• Remove the first and last occurrences of the repeating numbers from the list.

• Return the modified list.

A segmentation fault occurs when a program tries to access a memory location that it is not allowed to access.

• Segmentation faults commonly occur due to accessing an uninitialized pointer or accessing an array out of bounds.

• Here is an example code that causes a segmentation fault: int main() { int* ptr; *ptr = 10; return 0; }

1. Java supports multiple inheritance. 2. Reverse a string word by word.

• 1. Java supports multiple inheritance through interfaces. A class can implement multiple interfaces.

• 2. Split the string into words using split() method. Reverse the array of words and join them using join() method.

Check if a pair exists with given sum in given array.

• Iterate through the array and for each element, check if the difference between the given sum and the current element exists in the array.

• Use a hash table to store the elements of the array and their indices for faster lookup.

• If the sum is even, check for pairs of equal values that add up to half the sum.

• If the array is sorted, use two pointers to traverse the array from both ends towards the middle.

Dynamic Programming is a programming concept that solves complex problems by breaking them down into smaller overlapping subproblems.

• Dynamic Programming is based on the principle of optimal substructure and overlapping subproblems.

• It uses memoization or tabulation techniques to store and reuse solutions to subproblems.

• Dynamic Programming is often used to optimize time and space complexity in algorithms.

• Examples of problems that can be solved using Dynamic Programming include ...read more

I have worked on a project outside of Computer Science related to environmental conservation.

• Developed a mobile application to track and monitor endangered species in local wildlife reserves.

• Collaborated with a team of biologists and conservationists to gather data and design the app's features.

• Implemented features like GPS tracking, photo recognition, and data visualization to aid in species identification and conservation efforts.

Find the missing number from an array containing numbers from 1 to n-1.

• Calculate the sum of all numbers from 1 to n-1 using the formula n*(n-1)/2.

• Calculate the sum of all numbers in the array.

• Subtract the sum of array from the sum of all numbers to get the missing number.

To get left view, right view, and top view of a binary tree, perform level order traversal and keep track of the first node encountered at each level.

• Perform level order traversal of the binary tree

• Keep track of the first node encountered at each level for left view

• Keep track of the last node encountered at each level for right view

• For top view, use a map to store horizontal distance and node pairs

Code to find the next palindrome number after a given input.

• Convert the input number to a string to easily manipulate individual digits.

• Increment the input number by 1 and check if it is a palindrome.

• If not a palindrome, continue incrementing until a palindrome is found.

Understanding how a trained neural network works involves grasping the concept of layers, weights, biases, and activation functions.

• Neural networks consist of layers of interconnected nodes that process input data.

• Weights and biases are adjusted during training to minimize error and improve accuracy.

• Activation functions introduce non-linearity to the network, allowing it to learn complex patterns.

• Understanding backpropagation helps in grasping how neural networks learn from d...read more

Generate all permutations of balanced parentheses and store them in a vector.

• Use backtracking to generate all possible combinations of parentheses

• Check for balanced parentheses using a stack

• Store each valid combination in a vector

• Return the vector of permutations

A star program can be written using nested for loops in any programming language.

• Use two nested for loops to print the rows and columns of the star pattern.

• The number of rows and columns can be determined by the user input or a constant value.

• The star pattern can be created using asterisks or any other character.

• The number of for loops required depends on the complexity of the star pattern.

• For a simple star pattern, only one for loop may be required.

The time to burn one candle completely depends on the size of the candles and the rate at which they burn.

• The time to burn one candle completely is directly proportional to the size of the candle.

• The rate at which a candle burns can vary based on factors like the material of the candle, the wick, and the environment.

• For example, a larger candle may take longer to burn completely compared to a smaller candle, even if they are both made of the same material.

Reliability in networks is ensured through redundancy, fault tolerance, monitoring, and regular maintenance.

• Redundancy: Having backup components or paths to prevent single points of failure.

• Fault tolerance: Systems are designed to continue functioning even if a component fails.

• Monitoring: Constantly checking network performance and addressing issues proactively.

• Regular maintenance: Updating software, replacing hardware, and optimizing configurations to prevent failures.

• Exampl...read more

MongoDB is a NoSQL database while SQL is a relational database management system.

• MongoDB is schema-less, allowing for flexible data models.

• SQL databases use structured query language for defining and manipulating data.

• MongoDB is horizontally scalable, while SQL databases are vertically scalable.

• SQL databases are better suited for complex queries and joins.

• MongoDB is commonly used for big data and real-time applications.

• SQL databases are ACID compliant, ensuring data integrity...read more

Cubes are multidimensional data structures used for analysis and reporting. They differ from databases in their structure and purpose.

• Cubes store data in a multidimensional format, allowing for efficient analysis and reporting.

• They are designed to handle large volumes of data and provide fast query performance.

• Cubes use dimensions, measures, and hierarchies to organize and analyze data.

• Unlike databases, cubes are optimized for analytical processing rather than transactional p...read more

Stack and queue are data structures used to store and retrieve data in a specific order.

• Stack: undo/redo functionality in text editors, back button in web browsers

• Queue: printing jobs in a printer, waiting list for a ride at an amusement park

Multi vendor architecture offers flexibility but also introduces complexity and potential vendor lock-in.

• Advantages: flexibility to choose best-of-breed solutions, competition drives innovation, reduces dependence on a single vendor

• Disadvantages: increased complexity, potential for integration issues, vendor lock-in risk, increased management overhead

• Example: using multiple cloud providers for redundancy and cost optimization

• Example: using multiple software vendors for differ...read more

Scrum is an agile methodology used for software development and project management.

• It involves iterative and incremental development.

• A team works on a project in sprints, typically 2-4 weeks long.

• The team has daily stand-up meetings to discuss progress and plan for the day.

• The product owner prioritizes the backlog of work.

• At the end of each sprint, a review and retrospective are held to evaluate progress and plan for the next sprint.

Optimize performance by using code splitting, lazy loading, memoization, and minimizing re-renders.

• Use code splitting to load only necessary code for each route or component.

• Implement lazy loading to load components only when needed.

• Utilize memoization to cache expensive calculations or API calls.

• Minimize re-renders by using PureComponent or memo for functional components.

A SQL query to move a table from one schema to another.

• Use the ALTER TABLE statement to rename the table and move it to the new schema.

• Specify the new schema name in the ALTER TABLE statement.

• Ensure that the user executing the query has the necessary privileges to perform the operation.

The program offers hands-on experience with cutting-edge technologies and provides mentorship from industry experts.

• Access to cutting-edge technologies

• Mentorship from industry experts

• Hands-on experience with real-world projects