- Q1: Print all anagrams of a given string
- Q2: Print matrix in spiral order
- Q3: Delete n digits from a number such that the result is the minimum number
- Q4: Combine two sorted singly linked lists
- Q5: 9 Marbles and weighing machine
- Q6: 3 buckets and apples and oranges
- Q7: Max of two numbers without using any branching, if-else, loop and conditional operators
- Q8: Finding equillibrium index
- Q9: Frog trying to cross river over falling leaves (no solution to this question)
- Q10: Given two keys K1 and K2, print all the values in the range K1 and K2 from a given BST
- Q11: Celebrity problem

- Q1: Root to leaf path equal to a given number n.
- Q2: Print all pairs of anagrams in a given array of strings.
- Q3: Level order traversal of a tree.
- Q4: Given an array of words, print all anagrams together.
- Q5: Convert a given tree into a sum tree.
- Q6: Delete middle element of a linked list.
- Q7: Convert a binary tree into a circular double linked list.
- Q8: Print nodes at K distances from the root.
- Q9: Even occuring elements in an array of limited range.
- Q10: Print first n numbers with exactly two bits set.
- Q11: Find the element in an array that appears once.

- Q1: Find the maximum repeating number in O(n) and O(1) extra space.
- Q2: Anagram substring search (or search for all permutatins)
- Q3: Remove all duplicates from a given string.
- Q4: Flattening a linked list.
- Q5: Rearrange a given list so that it consists of alternating min-max elements.
- Q6: Design a tiny URL or URL shortener.
- Q7: Convert a given number to words.
- Q8: Longest even length substring such that sum of the first and second half is the same
- Q9: Find the excel column name from a given column number.

- Q1: Rotate square matrix in-place by 90 degrees.
- Q2: Array rotation (5 methods)
- Q3: Snake and Ladder problem: minimum number of throws required to reach the last cell.
- Q4: Finding the number of islands.
- Q5: Stepping numbers (2 methods)
- Q6: Print all possible words from phone digits.
- Q7: Square root of an integer.
- Q8: Find two missing numbers (3 methods)
- Q9: Find the missing number (2 methods)

- Q1: Boundary traversal of a binary tree.
- Q2: Lowest Common Ancestor (LCA) problem.
- Q3: Reverse level order traversal.
- Q4: Level order traversal in spiral form.
- Q5: Implement Queue using stacks.
- Q6: Intersection of two linked lists.
- Q7: Determine if two trees are identical.
- Q8: Detect cycle in a directed graph.
- Q9: Clone a linked list where each node has next and random pointer.
- Q10: Check if two nodes are on the same path in a tree.

- Q1: Sorted Linked List to Balanced BST
- Q2: Construct a binary tree from a given parent array representation.
- Q3: Height of a binary tree represented by parent array.
- Q4: The bedlam in the party (BFS solution)
- Q5: Connect the nodes at the same level in a tree.
- Q6: Merge two sorted linked lists.
- Q7: Delete the middle of the linked list.
- Q8: Find the intersection point of two linked lists.
- Q9: Reverse a linked list (recursive and non-recursive)
- Q10: Check whether circular linked list or not.
- Q11: Detect loop in a linked list.
- Q12: Detect and remove loop in a linked list.

- Q1: Check if a tree is balanced or not.
- Q2: Diameter of a binary tree.
- Q3: Delete a node in a linked list when the head of the list is not given.
- Q4: Maximum width of a tree.
- Q5: Convert to mirror tree.
- Q6: Program to check if a binary tree is BST or not.
- Q7: Sorted insert for circular linked list.
- Q8: Merge two sorted linked list in reverse order.
- Q9: Sort a linked-list of 0s, 1s and 2s.
- Q10: Pairwise swap elements of a given linked list by changing links.

- Q1: Reverse a linked list in groups of a given size.
- Q2: LRU implementation
- Q3: Calculate pow(x, n)
- Q4: Modular exponentiation
- Q5: Find the numbers from an array containing (2*n+2) positive numbers.
- Q6: Find subarray with a given sum.
- Q7: Reverse words in a given string.
- Q8: Find the minimum element in a sorted and rotated array.
- Q9: Find if two rectangles overlap.
- Q10: Check whether a given point lies inside or outside a polygon.

- Q1: Check if a number is a multiple of 3
- Q2: Find the position of the only set bit
- Q3: Design a website hit counter.
- Q4: Maximal subarray problem (Kadane's algorithm)
- Q5: Move all zeroes to the end of the array.
- Q6: Sum of absolute differences of all pairs in a given array.
- Q7: Find the next greater number with the same set of digits.
- Q8: Lexicographically next permutation.
- Q9: Search an element in a sorted and rotated array.
- Q10: Find the duplicates in O(n) time and O(1) extra space in an array containing elements from 0 to (n-1).

- Q1: Computational complexity of finding the nth Fibonacci number.
- Q2: Count the number of occurrences of an element x in a sorted array in O(log(n))
- Q3: Given a matrix of distinct values and a sum, find pairs with a given sum such that elements of the pair are in different rows.
- Q4: Trapping the rain water (given an elevation map)
- Q5: Left view of a binary tree.
- Q6: Find the kth smallest element in a BST.
- Q7: Count the number of ways to reach the nth stair.
- Q8: Find the plus (+) pattern of maximum size in a 2D array of 1s and 0s.
- Q9: Minimum cost path (dynamic programming solution)
- Q10: Check if two linked lists merge. If so, where.

Sample Technical Interview Questions - Part 1