Reverse a string – Asked in: Infosys
Check if a string is a palindrome – Asked in: Capgemini
Find the factorial of a number – Asked in: Wipro
Find the largest number in an array – Asked in: TCS
Find the smallest number in an array – Asked in: Cognizant
Calculate the sum of array elements – Asked in: Infosys
Count even and odd numbers in an array – Asked in: Accenture
Count vowels and consonants in a string – Asked in: IBM
Swap two numbers – Asked in: TCS
Print Fibonacci series – Asked in: Infosys
Check if a number is prime – Asked in: Wipro
Find GCD of two numbers – Asked in: TCS
Find LCM of two numbers – Asked in: Infosys
Check Armstrong number – Asked in: Capgemini
Check Perfect number – Asked in: Cognizant
Reverse a number – Asked in: IBM
Count digits in a number – Asked in: Accenture
Print prime numbers in a range – Asked in: TCS
Print multiplication table – Asked in: Infosys
Find power of a number – Asked in: Wipro
Convert binary to decimal – Asked in: Capgemini
Convert decimal to binary – Asked in: Cognizant
Remove duplicates from an array – Asked in: Infosys
Find frequency of elements in an array – Asked in: Accenture
Sort array using bubble sort – Asked in: TCS
Sort array using selection sort – Asked in: Wipro
Find second largest element – Asked in: IBM
Find second smallest element – Asked in: Capgemini
Merge two arrays – Asked in: Infosys
Find missing number in array (1 to N) – Asked in: TCS
Count occurrences of a character in string – Asked in: Wipro
Capitalize first letter of each word in string – Asked in: Accenture
Remove all white spaces from string – Asked in: Infosys
Replace character in string – Asked in: Cognizant
Remove special characters from string – Asked in: TCS
Compare two strings – Asked in: Wipro
Find length of string without using length() – Asked in: Capgemini
Convert lowercase to uppercase – Asked in: Infosys
Convert string to integer – Asked in: IBM
Convert integer to string – Asked in: Accenture
Find ASCII value of character – Asked in: TCS
Check if strings are anagrams – Asked in: Capgemini
Count number of words in string – Asked in: Infosys
Remove duplicates from string – Asked in: Wipro
Check if array is sorted – Asked in: Cognizant
Implement linear search – Asked in: TCS
Implement binary search – Asked in: Infosys
Find intersection of two arrays – Asked in: Wipro
Find union of two arrays – Asked in: Accenture
Find sum of digits of number – Asked in: Capgemini

...

Find common elements in three sorted arrays – Asked in: Infosys
Check for pair with given sum in array – Asked in: Capgemini
Find majority element in array – Asked in: TCS
Kadane’s Algorithm – Max subarray sum – Asked in: Wipro
Check if array contains duplicate – Asked in: Infosys
Check if two strings are isomorphic – Asked in: IBM
Longest common prefix – Asked in: Accenture
Longest substring without repeating characters – Asked in: TCS
Group anagrams – Asked in: Wipro
Check if linked list is palindrome – Asked in: Infosys
Find middle of linked list – Asked in: Capgemini
Detect loop in linked list – Asked in: TCS
Remove Nth node from end – Asked in: Cognizant
Merge two sorted linked lists – Asked in: Wipro
Reverse a linked list – Asked in: Infosys
Find intersection of two linked lists – Asked in: Accenture
Add two numbers as linked list – Asked in: IBM
Remove duplicates from sorted list – Asked in: Capgemini
Delete node in a linked list – Asked in: TCS
Odd even linked list – Asked in: Wipro
Detect and remove loop in linked list – Asked in: Infosys
Implement stack using arrays – Asked in: Capgemini
Implement queue using arrays – Asked in: TCS
Implement circular queue – Asked in: Cognizant
Infix to postfix conversion – Asked in: Wipro
Evaluate postfix expression – Asked in: Infosys
Next greater element – Asked in: Accenture
Balanced parentheses – Asked in: IBM
Stock span problem – Asked in: Capgemini
LRU Cache implementation – Asked in: TCS
Insert interval – Asked in: Wipro
Merge intervals – Asked in: Infosys
Minimum platforms required – Asked in: Capgemini
Job scheduling problem – Asked in: TCS
N meeting in one room – Asked in: Wipro
Activity selection problem – Asked in: Infosys
Fractional knapsack problem – Asked in: IBM
0/1 Knapsack problem – Asked in: Accenture
Longest common subsequence – Asked in: TCS
Longest palindromic subsequence – Asked in: Capgemini
Coin change problem – Asked in: Infosys
Rod cutting problem – Asked in: Cognizant
Minimum number of coins – Asked in: Accenture
Subset sum problem – Asked in: Wipro
Word break problem – Asked in: IBM
Longest increasing subsequence – Asked in: TCS
Maximum product subarray – Asked in: Infosys
Edit distance – Asked in: Capgemini
Boolean parenthesization problem – Asked in: Wipro
Palindrome partitioning – Asked in: TCS

...

Two Sum Problem – Asked in: TCS
Move zeros to end of array – Asked in: Wipro
Rotate array by K elements – Asked in: Infosys
Check if subarray with 0 sum exists – Asked in: Capgemini
Find longest subarray with given sum – Asked in: Cognizant
Maximum sum increasing subsequence – Asked in: Infosys
Trapping Rain Water – Asked in: TCS
Minimum jumps to reach end – Asked in: Wipro
Chocolate Distribution Problem – Asked in: Capgemini
Activity Selection (Greedy) – Asked in: Accenture
Find missing and repeating number – Asked in: TCS
Find duplicate number (Floyd's Cycle) – Asked in: Infosys
Set Matrix Zeroes – Asked in: Wipro
Spiral Matrix – Asked in: Capgemini
Search in a sorted 2D matrix – Asked in: IBM
Find peak element – Asked in: Accenture
Kth smallest element in array – Asked in: TCS
Kth largest element using heap – Asked in: Infosys
Sliding window maximum – Asked in: Wipro
First negative integer in window – Asked in: Capgemini
Check if brackets are balanced – Asked in: Infosys
Implement queue using stack – Asked in: IBM
Implement stack using queue – Asked in: Accenture
LRU Cache – Asked in: Capgemini
LFU Cache – Asked in: Wipro
Flatten a linked list – Asked in: TCS
Clone a linked list with random pointer – Asked in: Infosys
Sort a stack – Asked in: Capgemini
Delete middle of a stack – Asked in: Wipro
Insert at bottom of stack – Asked in: TCS
Check for balanced tree – Asked in: Infosys
Diameter of binary tree – Asked in: Capgemini
Invert binary tree – Asked in: IBM
Zigzag traversal of binary tree – Asked in: Accenture
Boundary traversal of binary tree – Asked in: TCS
Top view of binary tree – Asked in: Infosys
Bottom view of binary tree – Asked in: Capgemini
Vertical order traversal – Asked in: Wipro
Symmetric tree – Asked in: Infosys
Binary tree from inorder & preorder – Asked in: IBM
Lowest common ancestor in binary tree – Asked in: Capgemini
Max depth of binary tree – Asked in: TCS
Sum root to leaf numbers – Asked in: Infosys
Path sum – Asked in: Wipro
Binary tree level order traversal – Asked in: Accenture
Convert binary tree to doubly linked list – Asked in: Capgemini
Serialize and deserialize binary tree – Asked in: Infosys
Check subtree of another tree – Asked in: TCS
Construct tree from postorder and inorder – Asked in: Capgemini
Flatten binary tree to linked list – Asked in: Wipro

Find all duplicates in array – Asked in: Infosys
Find first and last position of element – Asked in: TCS
Count number of subarrays with sum k – Asked in: Capgemini
Find pivot index – Asked in: Cognizant
Max consecutive ones – Asked in: Wipro
Missing number – Asked in: Accenture
Min size subarray sum – Asked in: Infosys
Find all numbers disappeared – Asked in: TCS
Minimum operations to make array equal – Asked in: IBM
Merge two sorted arrays – Asked in: Capgemini
Check array is sorted and rotated – Asked in: Wipro
Best time to buy and sell stock – Asked in: Infosys
Subarray product less than k – Asked in: Accenture
Find target indices after sorting – Asked in: TCS
Rearrange array elements by sign – Asked in: Wipro
Maximum average subarray I – Asked in: Capgemini
Find kth positive missing number – Asked in: Infosys
Number of good pairs – Asked in: Cognizant
Intersection of two arrays – Asked in: IBM
Relative sort array – Asked in: Capgemini
Check if number is power of two – Asked in: Wipro
Single number – Asked in: TCS
Hamming weight – Asked in: Infosys
Count set bits – Asked in: Accenture
Find XOR of numbers from 1 to n – Asked in: IBM
Sum of two integers without + - – Asked in: Capgemini
Reverse bits – Asked in: Wipro
Add binary – Asked in: Infosys
Bitwise AND of numbers range – Asked in: TCS
Find missing number using XOR – Asked in: Accenture
Subsets – Asked in: Wipro
Permutations – Asked in: Infosys
Combination sum – Asked in: Capgemini
Word search – Asked in: TCS
N queens – Asked in: IBM
Palindrome partitioning – Asked in: Accenture
Letter case permutation – Asked in: Cognizant
Generate parentheses – Asked in: Infosys
Sudoku solver – Asked in: Wipro
Restore IP addresses – Asked in: TCS
Gray code – Asked in: Capgemini
Combination sum II – Asked in: Infosys
Combinations – Asked in: Wipro
Subsets II – Asked in: Accenture
Path sum II – Asked in: TCS
Letter combinations of a phone number – Asked in: Capgemini
Permutations II – Asked in: Infosys
Word break – Asked in: Wipro
Palindrome partitioning II – Asked in: IBM
Minimum number of swaps to make string balanced – Asked in: Cognizant

...

Validate Binary Search Tree – Asked in: Infosys
Lowest Common Ancestor of a BST – Asked in: Wipro
Binary Tree Inorder Traversal – Asked in: TCS
Construct Binary Tree from Inorder and Preorder – Asked in: Capgemini
Populating Next Right Pointers – Asked in: IBM
Flatten a Multilevel Doubly Linked List – Asked in: Infosys
Insert into a Binary Search Tree – Asked in: Cognizant
Sum of Left Leaves – Asked in: Wipro
Maximum Depth of N-ary Tree – Asked in: Accenture
Convert Sorted Array to BST – Asked in: TCS
Construct String from Binary Tree – Asked in: Infosys
Average of Levels in Binary Tree – Asked in: Capgemini
Binary Tree Tilt – Asked in: Wipro
Path Sum III – Asked in: Cognizant
Find Duplicate Subtrees – Asked in: Accenture
Construct Binary Tree from String – Asked in: IBM
Binary Tree Cameras – Asked in: TCS
Binary Tree Coloring Game – Asked in: Infosys
All Nodes Distance K in Binary Tree – Asked in: Capgemini
Recover Binary Search Tree – Asked in: Wipro
Boundary of Binary Tree – Asked in: Cognizant
Binary Tree Right Side View – Asked in: Infosys
Same Tree – Asked in: Capgemini
Count Complete Tree Nodes – Asked in: TCS
Binary Tree Paths – Asked in: IBM
Sum of Nodes with Even-Valued Grandparent – Asked in: Accenture
Longest ZigZag Path in Binary Tree – Asked in: Wipro
Tree Diameter – Asked in: Infosys
Count Good Nodes in Binary Tree – Asked in: Capgemini
Binary Search Tree Iterator – Asked in: Cognizant
Serialize and Deserialize BST – Asked in: IBM
Delete Node in a BST – Asked in: Wipro
Kth Smallest Element in BST – Asked in: Infosys
Validate Stack Sequences – Asked in: Capgemini
Check Completeness of a Binary Tree – Asked in: TCS
Maximum Width of Binary Tree – Asked in: Accenture
Find Largest Value in Each Tree Row – Asked in: Wipro
Cousins in Binary Tree – Asked in: Infosys
Vertical Order Traversal – Asked in: Cognizant
Binary Tree Postorder Traversal – Asked in: Capgemini
Sum of Root To Leaf Binary Numbers – Asked in: Wipro
Delete Leaves with a Given Value – Asked in: Infosys
Longest Univalue Path – Asked in: TCS
Find Bottom Left Tree Value – Asked in: IBM
Flip Equivalent Binary Trees – Asked in: Accenture
All Elements in Two BSTs – Asked in: Cognizant
Merge Two Binary Trees – Asked in: Capgemini
Binary Tree Level Order Traversal II – Asked in: Wipro
Path In Zigzag Labelled Binary Tree – Asked in: Infosys
Sum of Distances in Tree – Asked in: TCS