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

1. Heap – Max Heaps and Min Heaps
2. Conversions : Decimal ,Binary, Hex, Octal (All other possible combinations)
3. 90 Degrees Matrix conversion
4. Quick Sort + Applications
5. Merge Sort + Applications
6. Remove duplicates in a String — In place
7. Reverse a string – Inplace
8. Decide if 2 strings are anagrams or not ?
9. Binary Search
10. Reverse SLL without using any extra nodes
11. Maximum Sub array [Kadane Algorithm]
12. Find an element which is repeated more than n/2 times in a given set/array. [Moores Voting algorithm]
13. Find and element in rotated Binary sorted array
14. Implement power function without pow() function
15.  Verify if given linked list is circular/cyclic or Acyclic. Follow up can be to indicate the starting point of cycle
16. Implement Blocking queue
17. Find a pair in array that will sum up to particular number
18. Reverse a double linked list
19. Reverse pairs in SLL. i.e I/P : a->b->c->d->e->f O/p : b->a->d->c->f->e
20. Segregate even and odd nodes in a given linked list
21. Addition of 2 linked lists to separate one. (also learn inplace)
22. Convert SLL in to DLL (XOR based linked lists)
23. Circular shift an array of integer input array by ‘k’ number of elements
24. Search for a given pattern in text [Rabin Karp Algorithm]
25. atio() and itoa() implementations (ASCII to integer and Integer to ASCII)
26.  Binary Semaphores
27. Generate subsets of given set of integers
28. Generate all permutations of a given string
29. Level order Traversal
30. Inorder successor of a given node in BST (Binary Search Tree)
31. Find ‘k’ largest /smallest elements in a given array (Hint : can use heaps)
32. Heap Sort + applications
33. Find minimum length unsorted sub array on which storing them makes complete sorted array
34. Search if a given pattern exists in input text using Suffix Arrays
35. Re-arrange a string so that all same characters are ‘d’ distant apart
36. Knights tour problem
37. Rat in Maze [Back tracking]
38. Find out if two rectangles overlap or not
39. Find closest pair of points in the given plane
40. Find all subset of elements in the given set whose sum equals to a given target
41. Compute x^y such that it can work for floats and negative values
42. Find median of  given two input sorted arrays
43. Find total no of zeros in a given array of 1’s followed by 0’s
44. Find if there is any sub array which sums up to zero
45. Count number of inversions in a given array
46. Find minimum element in a rotated sorted array
47. Find the fixed point in the given array
48. Find the maximum sub array sum [D&C]
49. Count # of occurrences of a number in the sorted array
50. Find the max and min element in a given array with minimal number of comparisons
51. Check if a number is multiple of 3 or not ?
52. One line function to check if a number is power of 2 or not ?
53. Function to multiple a number by 7.
54. Function to multiple two numbers without using * product operator
55. Function to write Fibonacci series in iterative manner
56. Generate all prime numbers less than or equal to n [Sieve of Erastho..]
57. Given a number, Find the next biggest palindrome number
58. Implement logic for fair coin from biased coin
59.  Check if a number is divisible by 7 without mod operator
60. Find all the possible words from a phone keypad
61. Lexicographic sort of permutation of all words
62. Shuffle a given array / deck of cards [Fisher Yates Algo]
63. Reservoir Sampling Algorithm
64. Select ‘k’ random elements from ‘n’ elements
65. Given a number ‘n’. generate a pascal triangle out of it.
66. Write an exponential precision function [Taylor series]
67. Generate all prime factors of a given number
68. Generate all possible combination of ‘r’ elements in a given array of size ‘n’ [Probability Distribution Function]
69. Length of Longest common sub sequence of given sequence of numbers
70. Find minimum cost path in a given cost matrix
71. Total # of solutions in a coin change problem
72. Find binomial co-efficient
73. Knap-sack standard problem
74. Egg-Drop standard problem
75. Length of longest palindrome sequence
76. Palindrome Partitioning
77. Maximum Length of chained increasing pair
78. Find the middle of given linked list
79. Check if a given Single linked list is a palindrome or not
80. Insert/Delete/Search in max heap
81. Implement sizeof() operator
82. Find successor of given BST
83. Find all triangle triples in given array
84. Find lowest common ancestor of a given node
85. Return a single element by knocking out all other elements by ‘k’ [Josephus]
86. Given a sorted skewed binary tree, Create a BST out of it.
87. Given an array with integers, Output all the elements which were repeated exactly twice
88. Maximum depth/height/diameter of a given tree
89. Serialize and De serialize a given binary tree
90. Find single repeated or non-repeated number in conditional list. (XOR)
91. Implement “diff” in linux
92. Program to count # of set bits in a given integer.
93. Convert BST to doubly linked list
94. Convert integer to String without .toString()
95. GCD of two numerals
96. Given an array in post order traversal, check whether the given array is in BST or not
97. Reverse the words in a given English sentence
98. Get the median of a stream of large numbers
99. Print all the paths of a given Binary Tree from root to leaf
100. Modify array such that arr[i] == arr[arr[i]] Inplace
101. Find the missing number in a billion number list