Awesome Links and notes:

• Boyer-Moore Voting Algorithm
• Convert a binary tree to a DLL
• Egg dropping Puzzle
• Morris Traversal
• Manacher's Algorithm
• Awesome Graph problem

• Euler Circuit

  Cover all the edges exactly once without lifting up your pen.
  For Euler cycle
  
  1. Graph must be connected
  2. All vertices have even degrees
  For Euler Path
  
  1. Graph must be connected
  2. Exactly 2 verices have odd degrees
  Complexity of finding if euler cycle or euler path exists or not is O(V + E) which is the complexity of DFS.

• Hamiltonian Circuit

  This is NP hard problem and travelling salesman problem is based on this but using held karp algorithm we can solve it in exponential time using dynamic programming.