10+ SDE (Software Development Engineer) Interview Questions and Answers for Freshers

Given a binary search tree, print the path with sum k and minimum hops.

• Traverse the tree using DFS and keep track of the current path and its sum.

• If the current sum equals k, compare the current path with the minimum path found so far.

• If the current sum is greater than k, backtrack to the previous node and continue traversal.

• If the current sum is less than k, continue traversal.

• Return the minimum path found.

• Time complexity: O(nlogn) for balanced tree, O(n^2) for skewed tree.

Print all elements not present in a sorted array with time and space complexity.

• Iterate through array and print missing elements

• Use binary search for faster search

• Time complexity: O(n log n)

• Space complexity: O(1)

Print all elements not present in an unsorted array and give time and space complexity.

• Iterate through array and use a hashset to keep track of seen elements.

• Print elements not in hashset.

• Time complexity: O(n), Space complexity: O(n)

Agile is an iterative approach to software development that emphasizes flexibility and customer satisfaction.

• Agile involves breaking down projects into smaller, more manageable chunks called sprints.

• It prioritizes collaboration between developers, customers, and stakeholders.

• It allows for changes and adjustments to be made throughout the development process.

• It promotes continuous delivery and improvement.

• Advantages over waterfall model include faster time to market, increased...read more

Waterfall model is a linear sequential approach to software development.

• Advantages: clear and well-defined stages, easy to understand and manage, suitable for small projects with stable requirements

• Disadvantages: inflexible, difficult to make changes once a stage is completed, testing is done only at the end, not suitable for large or complex projects

• Stages: requirements gathering, design, implementation, testing, deployment, maintenance

• Example: building a house, where each s...read more

Finding an element in a rotated array

• Identify the pivot point where the array is rotated

• Divide the array into two sub-arrays based on the pivot point

• Perform binary search on the appropriate sub-array to find the element

• Handle edge cases like when the element is at the pivot point

SDLC is a process followed by software development teams to design, develop and test high-quality software.

• SDLC consists of several phases including planning, analysis, design, development, testing, deployment, and maintenance.

• Each phase has its own set of deliverables and objectives.

• SDLC models include Waterfall, Agile, and DevOps.

• SDLC helps ensure that software is developed efficiently, on time, and within budget.

• SDLC also helps ensure that software meets the needs of stake...read more

Find unique character from a string and optimize it

• Use a hash table to store the frequency of each character in the string

• Iterate through the hash table to find the character with frequency 1

• If there are multiple characters with frequency 1, return the first one

• Optimization: Stop iterating through the hash table once a character with frequency 1 is found

A database is a collection of organized data that can be easily accessed, managed, and updated.

• A database stores data in tables with rows and columns

• It allows for efficient data retrieval and manipulation

• Examples include MySQL, Oracle, and MongoDB

Dictionaries are a built-in data type in Python used to store key-value pairs.

• Keys must be unique and immutable.

• Values can be of any data type.

• Access values using keys.

• Add or modify values using keys.

• Use the 'in' keyword to check if a key exists in the dictionary.

• Use the 'len()' function to get the number of key-value pairs in the dictionary.