CCIS EXAM

Input Operations

provide the computing agent with data values from the outside world that it may then use in later instructions.

Counter

a variable that counts up from a loop

algorithm

a well-ordered collection of unambiguous and effectively computable operations that, when executed, produces a result and halts in a finite amount of time; A procedure for solving a mathematical problem in a finite number of steps that frequently involves repetition of an operation; broadly: a step-by-step method for accomplishing some task; an algorithm is an ordered sequence of instructions that is guaranteed to solve a specific problem; the central concept in computer science is the algorithm

Program documentation-

Part of the job of program documentation is to make clear any assumptions or restrictions about the input size the program was designed to handle.

Conditional Statements-

are the "question-asking" operations of an algorithm. They allow an algorithm to ask a yes/no question and select the next operation to perform on the basis of the answer to that question. There are a number of ways to phrase a question, but the most common conditional statement is the if/then/else statement

Sequential Search

it is the standard algorithm for searching an unordered list of values.

Infinite Loop

it makes no provision to terminate. It will essentially run forever

Variable

simply a named storage location that can hold a data value. A variable is often compared with a mailbox into which you can place a value and from which you can retrieve a value.

Natural Language-

the language we speak and write in our everyday lives.

Output Operations

- send results from the computing agent to the outside world.

Efficiency of algorithms (when best/worst case occurs)-

A convenient way to classify the time efficiency of algorithms is by examining the order of magnitude of the work they do; The study of the efficiency of algorithms is called the analysis of algorithms

Program maintenance

If the program is successful, people will want to use it for slightly different versions of the problem, which means they will want the program slightly enhanced to do more things. Therefore, after a program is written, it needs to be maintained, both to fix any errors that are uncovered through repeated usage with different input values and to extend the program to meet new requirements. A great deal of time and money are devoted to program maintenance. The person who has to modify a program, either to correct errors or to expand its functionality, often is not the person who wrote the original program. To make program maintenance as easy as possible, the algorithm the program uses should be easy to understand. Ease of understanding, clarity, "ease of handling"—whatever you want to call it—is a highly desirable characteristic of an algorithm.

Computing agents

In computer science terminology, the machine, robot, person, or thing carrying out the steps of the algorithm; an abstract concept representing any entity capable of understanding and executing our instructions

Sort Algorithms (sequential, selection)

Selection Sort- The selection sort "grows" a sorted subsection of the list from the back to the front. Sequential Sort: The worst-case behavior of the sequential search algorithm on a list of n items requires n comparisons, and if c is a constant factor representing the peripheral work, it requires cn total work; Sequential search is therefore an Θ(n) algorithm; The sequential search algorithm solves a very common problem: searching a list of items to locate a particular item. Another very common problem is that of sorting a list of items into order—either alphabetical or numerical order

Different types of instructions: sequential, conditional, iterative

Sequential operations- Carries out a single well-defined task. When that task is finished, the algorithm moves on to the next operation. Sequential operations are usually expressed as simple declarative sentences Conditional operations: These are the "question-asking" instructions of an algorithm. They ask a question, and the next operation is then selected on the basis of the answer to that question. Iterative operations: These are the "looping" instructions of an algorithm. They tell us not to go on to the next instruction but, instead, to go back and repeat the execution of a previous block of instructions.

Pattern Matching Algorithm

The process of searching for a special pattern of symbols within a larger collection of information

When are algorithms useless?

There are also problems for which it is theoretically possible to specify an algorithm but a computing agent would take so long to execute it that the solution is essentially useless.

Benchmarks

This type of comparative timing is called benchmarking. Benchmarks are useful for rating one machine against another and for rating how sensitive a particular algorithm is with respect to variations in input on one particular machine.

Library

a collection of useful, prewritten algorithms