The Class NP
DOES NOT MEAN EXPONENTIAL (although it probably is)
- All problems in P are in NP
- There are probably languages in EXPTIME that are not in NP
NP stands for Nondeterministically Polynomial
- NTM can answer NP problems in polytime
The more formal definition uses the idea of a verifier
- A verifier takes a string allegedly in the language, along with some piece of evidence.
- Using this evidence, it verifies that the string is indeed in the language.
- If the string is not in the language, or if the evidence isn’t right, it REJECTS