Table of Contents
- 1 What is adversary argument?
- 2 How do you prove an algorithm is lower bound?
- 3 What is adversary strategy?
- 4 What is adversary in algorithm?
- 5 What is the lower bound of the sorting problem?
- 6 What is lower bound theory in DAA?
- 7 What is the adversary model of cybercrime?
- 8 What is adaptive adversary?
- 9 What is the lower bound theory of time complexity?
- 10 What is 1212 lower bounds by problem reduction?
What is adversary argument?
The simplest proof technique is called an adversary argument. The idea is that an all-powerful malicious adversary (the dealer) pretends to choose an input for the algorithm (the tourist).
How do you prove an algorithm is lower bound?
Lower Bound – Let L(n) be the running time of an algorithm A(say), then g(n) is the Lower Bound of A if there exist two constants C and N such that L(n) >= C*g(n) for n > N. Lower bound of an algorithm is shown by the asymptotic notation called Big Omega (or just Omega).
Which sorting has best lower bound time complexity?
Therefore, any comparison based sorting algorithm must make at least nLog2n comparisons to sort the input array, and Heapsort and merge sort are asymptotically optimal comparison sorts.
What is adversary strategy?
If A is an algorithm that attempts to determine g(x) of an unknown input x by calling the oracle as few times as possible, then an adversary strategy against A simulates the oracle in a way that attempts to keep g(x) unknown as long as possible.
What is adversary in algorithm?
In computer science, an online algorithm measures its competitiveness against different adversary models. For deterministic algorithms, the adversary is the same as the adaptive offline adversary. For randomized online algorithms competitiveness can depend upon the adversary model used.
What is lower bound for sorting problem?
A lower bound for a problem is the worst-case running time of the best possible algorithm for that problem. To prove a lower bound of Ω(n lg n) for sorting, we would have to prove that no algorithm, however smart, could possibly be faster, in the worst-case, then n lg n.
What is the lower bound of the sorting problem?
A lower bound for a problem is the worst-case running time of the best possible algorithm for that problem. All sorting algorithms that we have seen so far use only comparisons to gain information about the input.
What is lower bound theory in DAA?
The lower bound theory is the method that has been utilized to establish the given algorithm in the most efficient way which is possible. This is done by discovering a function g (n) that is a lower bound on the time that any algorithm must take to solve the given problem.
What is the meaning of lower bound theory and how can it be used in solving algebraic problems?
What is the adversary model of cybercrime?
An adversary model is a formalization of an attacker in a computer or networked system. Depending on how complete this formalization is, the adversary may be an algorithm or may simply be a series of statements with regards to capabilities and goals.
What is adaptive adversary?
The adaptive online adversary is sometimes called the medium adversary. This adversary must make its own decision before it is allowed to know the decision of the algorithm. The adaptive offline adversary is sometimes called the strong adversary. This adversary knows everything, even the random number generator.
What is the upper bound theory of algorithm?
Upper Bound Theory: According to the upper bound theory, for an upper bound U (n) of an algorithm, we can always solve the problem in at most U (n) time.Time taken by a known algorithm to solve a problem with worse case input gives us the upper bound.
What is the lower bound theory of time complexity?
Lower Bound Theory: According to the lower bound theory, for a lower bound L (n) of an algorithm, it is not possible to have any other algorithm (for a common problem) whose time complexity is less than L (n) for random input. Also every algorithm must take at least L (n) time in worst case.
What is 1212 lower bounds by problem reduction?
12. 12 Lower Bounds by Problem Reduction Idea: If problem P is at least as hard as problem Q, then a lower bound for Q is also a lower bound for P. Hence, find problem Q with a known lower bound that can be reduced to problem P in question. Then any algorithm that solves P will also solve Q.
How do you find the lower bound of a problem?
12. 12 Lower Bounds by Problem Reduction Idea: If problem P is at least as hard as problem Q, then a lower bound for Q is also a lower bound for P. Hence, find problem Q with a known lower bound that can be reduced to problem P in question.