What:
Imagine having an unsolved problem A. If we have a similar solved problem B, then we may be able to transform / reduce A into B. This closely relates to reducing an NP problem into a P problem.
Simply: Can you reduce Problem A into problem B, solve B and in turn solve A in polynomial time? If you can, then that Algorithm (that reduces and solves A with B as a subroutine) is a polynomial time reduction.
Different Types of Reductions:
- Many-One Reduction: A specific type of polynomial-time reduction where each instance of problem A is mapped onto a single instance of problem B.