Concepts inA view selection algorithm with performance guarantee

Selection algorithm

In computer science, a selection algorithm is an algorithm for finding the kth smallest number in a list (such a number is called the kth order statistic). This includes the cases of finding the minimum, maximum, and median elements. There are, worst-case linear time, selection algorithms. Selection is a subproblem of more complex problems like the nearest neighbor problem and shortest path problems.
more from Wikipedia

Approximation algorithm

In computer science and operations research, approximation algorithms are algorithms used to find approximate solutions to optimization problems. Approximation algorithms are often associated with NP-hard problems; since it is unlikely that there can ever be efficient polynomial time exact algorithms solving NP-hard problems, one settles for polynomial time sub-optimal solutions.
more from Wikipedia

APX

In complexity theory the class APX (an abbreviation of "approximable") is the set of NP optimization problems that allow polynomial-time approximation algorithms with approximation ratio bounded by a constant (or constant-factor approximation algorithms for short). In simple terms, problems in this class have efficient algorithms that can find an answer within some fixed percentage of the optimal answer.
more from Wikipedia

Time complexity

In computer science, the time complexity of an algorithm quantifies the amount of time taken by an algorithm to run as a function of the size of the input to the problem. The time complexity of an algorithm is commonly expressed using big O notation, which suppresses multiplicative constants and lower order terms. When expressed this way, the time complexity is said to be described asymptotically, i.e. , as the input size goes to infinity.
more from Wikipedia

Trade-off

A trade-off (or tradeoff) is a situation that involves losing one quality or aspect of something in return for gaining another quality or aspect. It implies a decision to be made with full comprehension of both the upside and downside of a particular choice. And you are giving something away to get something back.
more from Wikipedia

D (programming language)

The D programming language is an object-oriented, imperative, multi-paradigm system programming language created by Walter Bright of Digital Mars. It originated as a re-engineering of C++, but even though it is mainly influenced by that language, it is not a variant of C++. D has redesigned some C++ features and has been influenced by concepts used in other programming languages, such as Java, Python, Ruby, C#, and Eiffel.
more from Wikipedia