100+ SDE & SDET Interview Questions With Answers

SDE/SDET Interview questions that will ramp up your interview preparation

Myself, Balaji Boggaram Ramanarayan – I bag experience in taking/preparing for interviews in several big companies and always felt sharing a few of them such that it might be useful for you in interview preparation.

Note: These questions might help you ramp up your speed in the path of preparing for SDE /SDET interviews in most techie companies.

SDE – Software Development Engineer
SDET – Software Development Engineer in Test

The must-know SDE/SDET Interview Questions

Heap – Max Heaps and Min Heaps
Conversions: Decimal, Binary, Hex, Octal (All other possible combinations)
90 Degrees Matrix conversion
Quick Sort + Applications
Merge Sort + Applications
Remove duplicates in a String — In place
Reverse a string – Inplace
Decide if 2 strings are anagrams or not?
Binary Search
Reverse SLL without using any extra nodes
Maximum Subarray [Kadane Algorithm]
Find an element that is repeated more than n/2 times in a given set/array. [Moores Voting algorithm]
Find and element in rotated Binary sorted array
Implement power function without pow() function
Verify if the given linked list is circular/cyclic or Acyclic. Follow up can be to indicate the starting point of the cycle
Implement Blocking queue
Find a pair in an array that will sum up to a particular number
Reverse a double linked list
Reverse pairs in SLL. i.e I/P : a->b->c->d->e->f O/p : b->a->d->c->f->e
Segregate even and odd nodes in a given linked list
Addition of 2 linked lists to separate one. (also learn inplace)
Convert SLL in to DLL (XOR based linked lists)
Circular shift an array of integer input array by ‘k’ number of elements
Search for a given pattern in the text [Rabin Karp Algorithm]
atio() and itoa() implementations (ASCII to integer and Integer to ASCII)
Binary Semaphores
Generate subsets of a given set of integers
Generate all permutations of a given string
Level order Traversal
The inorder successor of a given node in BST (Binary Search Tree)

SDE/SDET Interview Questions- you should be able to answer

Find ‘k’ largest /smallest elements in a given array (Hint: can use heaps)
Heap Sort + applications
Find minimum length unsorted subarray on which storing them makes a complete sorted array
Search if a given pattern exists in input text using Suffix Arrays
Re-arrange a string so that all same characters are ‘d’ distant apart
Knights tour problem
Rat in Maze [Back tracking]
Find out if two rectangles overlap or not
Where are the closest pair of points in the given plane
Find all subset of elements in the given set whose sum equals to a given target
Compute x^y such that it can work for floats and negative values
Find median of given two input sorted arrays
Find the total no of zeros in a given array of 1’s followed by 0’s
If there is any sub-array find the ones which sum up to zero
Count number of inversions in a given array
Find a minimum element in a rotated sorted array
Which is the fixed point in the given array
Find the maximum subarray sum [D&C]
Count # of occurrences of a number in the sorted array
Find the max and min element in a given array with a minimal number of comparisons

30+ Software Developer (SDE) / Software Developer In Test (SDET) Questions for you

Check if a number is multiple of 3 or not?
One line function to check if a number is the power of 2 or not?
Function to multiple a number by 7.
Which is the function to multiply two numbers without using * product operator
Function to write Fibonacci series in an iterative manner
Generate all prime numbers less than or equal to n [Sieve of Erastho..]
Given a number, Find the next biggest palindrome number
Implement logic for a fair coin from a biased coin
Check if a number is divisible by 7 without mod operator
Find all the possible words from a phone keypad
Lexicographic sort of permutation of all words
Shuffle a given array/deck of cards [Fisher Yates Algo]
Reservoir Sampling Algorithm
Select ‘k’ random elements from ‘n’ elements
Given a number ‘n’. generate a pascal triangle out of it.
Write an exponential precision function [Taylor series]
Generate all prime factors of a given number
Generate all possible combinations of ‘r’ elements in a given array of size ‘n’ [Probability Distribution Function]
Length of Longest common subsequence of a given sequence of numbers
Find minimum cost path in a given cost matrix
Total # of solutions in a coin change problem
Find binomial co-efficient
Knap-sack standard problem
Egg-Drop standard problem
Length of longest palindrome sequence
Palindrome Partitioning
Maximum Length of chained increasing pair
Find the middle of the given linked list
Check if a given Single linked list is a palindrome or not
Insert/Delete/Search in max heap
Implement sizeof() operator
Find successor of given BST
Locate all triangle triples in the given array
Find the lowest common ancestor of a given node
Return a single element by knocking out all other elements by ‘k’ [Josephus]

Find more Software Developer (SDE) / Software Developer In Test (SDET) Questions

Given a sorted skewed binary tree, Create a BST out of it.
Given an array with integers, Output all the elements which were repeated exactly twice
Maximum depth/height/diameter of a given tree
Serialize and Deserialize a given binary tree
Find a single repeated or non-repeated number in the conditional list. (XOR)
Implement “diff” in Linux
Program to count # of set bits in a given integer.
Convert BST to a doubly-linked list
Convert integer to String without.toString()
GCD of two numerals
Given an array in post-order traversal, check whether the given array is in BST or not
Reverse the words in a given English sentence
Get the median of a stream of large numbers
Print all the paths of a given Binary Tree from root to leaf
Modify array such that arr[i] == arr[arr[i]] Inplace
Find the missing number in a billion number list
Bitwise addition