Polynomial Time Nondeterministic Turing Machine Decision Problem Decidable Decision Problem Types of Problems: Decision Problem Search Problem Optimisation Problem Complexity Class P⊆NP⊆P−Space,NP−Space⊆EXPTIME Memebership vs. Hardness vs. Completeness Big-O Notation Problems: Independent Set Problem Independent Set Vertex Cover Problem Vertex Cover Clique Decision Problem Clique Dominating Set Problem Dominating Set