AQA A Level Computer Science 7517 : 4 - Theory of Computation Questions with 100% Correct Answers

What is the time complexity of an algorithm with no loops? Correct Answer Constant - O(1) What is the time complexity of an algorithm with a for/while loop? Correct Answer Linear - O(n) What is the time complexity of an algorithm with a nested loop? Correct Answer Polynomial - O(n^number of loops) What is the time complexity of an algorithm that halves a data set? Correct Answer Logarithmic - O(logn) What is the time complexity of a recursive algorithm? Correct Answer Exponential - O(2^n) Explain the two forms of abstraction Correct Answer Representational abstraction - removing unnecessary details. Abstraction by generalisation - a grouping of common characteristics to arrive at a hierarchical relationship of the 'is a kind of' type. What is information hiding? Correct Answer The process of hiding all details of an object that do not contribute to its essential characteristics. What is procedural abstraction? Correct Answer Breaking down a complex model into a series of reusable procedures, abstracting actual values away to achieve a method. What is functional abstraction? Correct Answer Disregarding the particular mthod of procedural abstraction to result in a function. What is data abstraction? Correct Answer Abstracting away specific details of how data is represented to create new kinds of data structures from previously defined data structures. What is problem abstraction/reduction? Correct Answer Removing details from a problem until it is represented in a way that is solvable, as it is similar to a problem that has already been solved.