Karp's 21 NP-complete problems

Karp's 21 NP-complete problems are a group of computational challenges identified by Richard Karp in 1972. These problems are related to finding solutions efficiently in cases where verifying a given solution is easy, but discovering the solution itself may be very difficult and time-consuming as problems grow larger. Examples include the traveling salesman problem, scheduling, and 3D matching. Their importance lies in demonstrating that if a quick method can solve any one of these problems efficiently, then all NP-complete problems can be solved quickly, which would revolutionize computer science by making many complex problems more manageable.