In mathematics and computer science, an algorithm (/ˈælɡərɪðəm/ ( listen)) is an unambiguous specification of how to solve a class of problems. Algorithms can perform calculation, data processing, and automated reasoning tasks.

P versus NP

1. P
   • The general class of questions for which some algorithm can provide an answer in polynomial time is called "class P" or just "P".
   • P usually means Deterministic Problem which can say True of False in a polynomial time.
   • P is also known as consists of certain set of Decision Problems like Checklist.
2. NP
   • The class of questions for which an answer can be verified in polynomial time is called NP, which stands for "Non-deterministic Polynomial time".