Table of Contents
What do you mean by polynomial time verification?
Polynomial verification of a solution. For a recognition problem, if we are given a guess of a solution we want to verify if this solution can help. us answer the problem. If we can “doublecheck” that the guess is a solution in polynomial time, we say that we can verify the solution in polynomial time.
How do you find the polynomial time?
An algorithm is said to be of polynomial time if its running time is upper bounded by a polynomial expression in the size of the input for the algorithm, that is, T(n) = O(nk) for some positive constant k.
What is polynomial time reduction algorithm?
A polynomial-time Turing reduction from a problem A to a problem B is an algorithm that solves problem A using a polynomial number of calls to a subroutine for problem B, and polynomial time outside of those subroutine calls. Polynomial-time Turing reductions are also known as Cook reductions, named after Stephen Cook.
For which class of problems we can verify the solution in polynomial time?
The class of questions for which an answer can be verified in polynomial time is NP, which stands for “nondeterministic polynomial time”. An answer to the P versus NP question would determine whether problems that can be verified in polynomial time can also be solved in polynomial time.
What is Reducibility in DAA?
Reducibility for any problem (NP-hard or any other) means the possibility to convert problem A into other problem B. If we know the complexity of problem B then the complexity of problem A is at least the same as the complexity of problem A.
What is polynomial time and exponential time?
Polynomial time. A polynomial is a sum of terms that look like Constant * x^k Exponential means something like Constant * k^x. (in both cases, k is a constant and x is a variable). The execution time of exponential algorithms grows much faster than that of polynomial ones.
How do I lower my NP?
We can show that our new problem is NP-Hard by reducing another known NP-Hard problem to it in polynomial time….Show that the problem is NP-Hard
- Step 1 – Transform Input.
- Step 2 – Use Blackbox for Problem A.
- Step 3 – Transform Solution.
- Step 4 – Provide Proof.
What is a polynomial time verifier?
•A polynomial time verifier is a verifier that runs in polynomial time in the length of w. •A language A is polynomially verifiable if it has a polynomial time verifier. •Def: NP is the class of languages that have polynomial time verifiers.
What is a polynomial time problem?
Problemsthat can be solved by a polynomial-time algorithm are called tractableproblems. For example, most algorithms on arrays can use the array size, n, as the input size. Tofind the largest element in an array requires a single pass through the array, so thealgorithm for doing this is O(n), or linear time.
Is there a polynomial-time solution for every class NP-complete problem?
The class NP-complete (NPC) problems consist of a set of decision problems (a subset of class NP) that no one knows how to solve efficiently. But if there were a polynomial solution for even a single NP-complete problem, then every problem in NPC will be solvable in polynomial time.
Is there a polynomial time algorithm for creating a 3-color graph?
There exists a polynomial time algorithm for this. But deciding whether this can be done with 3 colors is hard, and there is no polynomial time algorithm for it. Fig: Example of 3-colorable and non-3-colorable graphs.