1. Given a binary string, count number of substrings that start and end with 1
  2. Given a string, find its first non-repeating character
  3. Generate n-bit Gray Codes
  4. Function to check if a singly linked list is palindrome
  5. Floor in a Sorted Array
  6. Find the transition point in a binary array
  7. Find the two numbers with odd occurrences in an unsorted array
  8. Find the largest subarray with 0 sum
  9. Find the maximum element in an array which is first increasing and then decreasing
  10. Find the maximum repeating number in O(n) time and O(1) extra space
  11. Find the element before which all the elements are smaller than it, and after which all are greater
  12. Find the row with maximum number of 1s
  13. Find nth Magic Number
  14. For each element in 1st array count elements less than or equal to it in 2nd array
  15. Reverse Level Order Traversal
  16. Print BST keys in the given range
  17. Print a pattern without using any loop
  18. Print all subarrays with 0 sum
  19. Remove every k-th node of the linked list
  20. Merge two sorted lists
  21. Merge two sorted linked lists such that merged list is in reverse order
  22. Mobile Numeric Keypad Problem
  23. Print all Jumping Numbers smaller than or equal to a given value
  24. Write Code to Determine if Two Trees are Identical
  25. Infix to Postfix