Section 10 Computational Thinking

Computation thinking

• Computation Thinking is the process of thinking how a problem can be solved.
• This invoves 2 basic steps:
1. Formulate the problem as a computational program
2. Try to construct an algorithm to solve the problem

Abstraction

• Abstraction involves filtering out (essentially, ignoring) the characteristics that we don't need in order to concentrate on those that we do.
• Example: The operation of a mobile phone. You can make a call, send a message, or browse the internet without needing to know the complex workings behind these operations.

Abstraction Applied to High level programming languages

Abstraction is the most important feature of high level programming languages such as Python, C#, Java and hundreds of other languages written for different purposes. To understand why, we need to look at the different generations of programming languages:

• The first generation of language was machine code - programmers entered the binary Os and 1s that the computer understands.
• The second generation was an improvement; mnemonic codes were used to represent instructions.
• The third generation of languages, starting with BASIC and FORTRAN in the 1960s, used statements like X= A +5,

A famous example of abstraction is the city Königsberg and its bridge problem.

Computational Problems

At its most abstract level, a computational problem can be represented by a simple diagram:

• Input: is the information relevant to the problem, which could for example be passed as parameters to a subroutine.
• Output:is the solution to the problem.

Preconditions

In order to make sure a function never crashes, the function must pass a test-case for an empty input or a precondition must be specified

Advantages of Precondtions:

• Specifying preconditions as part of the documentation of a subroutine ensures that the user knows what checks, if any, must be carried out before calling the subroutine.
• Clear documentation of inputs, outputs and preconditions helps to make the subroutine reusable.

Nature and benefits of Caching

Caching is another aspect of thinking ahead, this time done automatically by the operating system rather than the programmer. Caching is the temporary storage of program instructions or data that have been used once and may be needed again shortly. The last few instructions of a program may be stored in cache memory for quick retrieval.

Procedural Abstraction

• It means using a procedure to carry out a sequence of steps, such as functions in high level programming language

Decomposition

• Decomposition involves breaking down a complex problem or system into smaller parts that are more manageable and easier to understand. The smaller parts can then be examined and solved, or designed individually, as they are simpler to work with.