1. Prime Arrangements
  2. Sieve of Eratosthenes
  3. Set Mismatch
  4. Peak Index in a Mountain Array
  5. Maximize Distance to Closest Person
  6. Backspace String Compare
  7. License Key Formatting
  8. Count all Grandparent-Parent-Child Triplets in a binary tree whose sum is greater than X
  9. Longest Uncommon Subsequence I
  10. Numbers having Unique (or Distinct) digits
  11. Burn the binary tree starting from the target node
  12. Generate all palindromic numbers less than n
  13. Distribute Coins in Binary Tree
  14. Print array elements in alternatively increasing and decreasing order
  15. Rearrange an array in maximum minimum form
  16. Building Bridges
  17. Count the Number of Binary Search Trees present in a Binary Tree
  18. Implement a stack using single queue
  19. Sum of numbers with exactly 2 bits set
  20. Ways to paint stairs with two colors such that two adjacent are not yellow
  21. Select a Random Node from a Singly Linked List
  22. External Sorting
  23. Pair with a given sum in BST
  24. Find smallest missing element from a sorted array
  25. Iterative Quick Sort