# 100+ Interview questions for Software Developer (SDE) / Software Developer In Test (SDET)

**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 path of preparing to SDE /SDET interviews in most techie companies. *

** SDE – Software Development Engineer**

** SDET – Software Development Engineer in Test **

- 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 Sub array [Kadane Algorithm]
- Find an element which 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 given linked list is circular/cyclic or Acyclic. Follow up can be to indicate the starting point of cycle
- Implement Blocking queue
- Find a pair in array that will sum up to 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 text [Rabin Karp Algorithm]
- atio() and itoa() implementations (ASCII to integer and Integer to ASCII)
- Binary Semaphores
- Generate subsets of given set of integers
- Generate all permutations of a given string
- Level order Traversal
- Inorder successor of a given node in BST (Binary Search Tree)
- Find ‘k’ largest /smallest elements in a given array (Hint : can use heaps)
- Heap Sort + applications
- Find minimum length unsorted sub array on which storing them makes 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
- Find 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 total no of zeros in a given array of 1’s followed by 0’s
- Find if there is any sub array which sums up to zero
- Count number of inversions in a given array
- Find minimum element in a rotated sorted array
- Find the fixed point in the given array
- Find the maximum sub array sum [D&C]
- Count # of occurrences of a number in the sorted array
- Find the max and min element in a given array with minimal number of comparisons
- Check if a number is multiple of 3 or not ?
- One line function to check if a number is power of 2 or not ?
- Function to multiple a number by 7.
- Function to multiple two numbers without using * product operator
- Function to write Fibonacci series in 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 fair coin from 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 combination of ‘r’ elements in a given array of size ‘n’ [Probability Distribution Function]
- Length of Longest common sub sequence of 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 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
- Find all triangle triples in given array
- Find lowest common ancestor of a given node
- Return a single element by knocking out all other elements by ‘k’ [Josephus]
- 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 De serialize a given binary tree
- Find single repeated or non-repeated number in conditional list. (XOR)
- Implement “diff” in linux
- Program to count # of set bits in a given integer.
- Convert BST to 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
- Bit wise addition