Easy Level

1. Level Order Tree Traversal
2. Check if two trees are Mirror
3. Level Order Tree Traversal
4. Print all nodes that don’t have sibling
5. A Product Array Puzzle
6. Copy set bits in a range
7. Find the element that appears once in a sorted array
8. Given a string, find its first non-repeating character
9. Implement Stack using Queues
10. Intersection of two Sorted Linked Lists
11. Majority Element
12. Median of two sorted arrays
13. Print a given matrix in spiral form
14. Implement Queue using Stacks
15. Search an element in a sorted and rotated array
16. Write a program function to detect loop in a linked list

Medium Level

1. Count BST nodes that lie in a given range
2. Dynamic Programming | Set 11 (Egg Dropping Puzzle)
3. Find the number of islands | Set 1 (Using DFS)
4. Find the largest BST subtree in a given Binary Tree | Set 1
5. Program to find amount of water in a given glass
6. Given a matrix of ‘O’ and ‘X’, find the largest subsquare surrounded by ‘X’
7. Largest Sum Contiguous Subarray
8. Minimum Number of Platforms Required for a Railway/Bus Station
9. Trie | (Insert and Search)
10. Write a function to get the intersection point of two Linked Lists.