PDF | On Aug 1, , Nicholas Bennett and others published Introduction to Algorithms and Pseudocode. Pseudo-code is an informal way to express the design of a computer program or an algorithm in. The aim is to get the idea quickly and also easy to read. Pseudo Code Practice Problems: Listed below is a brief explanation of Pseudo code as well as a list of examples and solutions. Pseudo code. Pseudo code can .

Pseudo Code Pdf

Language:English, German, Arabic
Genre:Politics & Laws
Published (Last):10.07.2016
ePub File Size:19.50 MB
PDF File Size:17.77 MB
Distribution:Free* [*Registration needed]
Uploaded by: MAMMIE

ALGORITHMS, FLOWCHARTS, DATA TYPES. AND PSEUDOCODE. ALGORITHMS. The term algorithm originally referred to any computation performed via. What is Pseudocode? An algorithm is a sequence of instructions to solve a well- formulated computational problem specified in terms of its input and output. Pseudocode What is pseudocode? Pseudocode is a simplified, half-English, half-code outline of a com- puter program. Why use it? • Because it can help.

Is every object name used in the pseudocode clearly understood by the target audience? If you find that a section of pseudocode needs elaboration or it doesn't explicitly outline a step that someone else might forget, go back and add the necessary information. Open a plain-text editor. Define your program. While not strictly necessary, writing a one- or two-sentence line at the top of the document will make clear from the beginning the intent of the program: This program will request a greeting from the user.

If the greeting matches a specific response, the response will be delivered; if not, a rejection will be delivered.

Write the opening sequence. Your first command—that is, the first thing your program should do upon running—should be the first line: Add the next line. In this example, the user should prompt the next line of dialogue: Add the call to action.

In this example, the user will be prompted for a greeting: Show the user a list of responses. Not good. Request input from the user. This is where the program will ask the user to enter a response: Create "if" commands for the user's input. Since there are multiple responses the user can select, you'll want to add multiple results based on their selected response: Add an error message.

In the event that the user incorrectly chooses a response, you can have an error message ready: Add any other components of the program. Go through your document and add or flesh out any details to ensure that both you and anyone reading the document will understand its meaning. As per this method's example, your final pseudocode document should look something like this: Save your document.

Pseudocode isn't real code, but details what a program should do step by step. Knowing how to write code is necessary to writing meaningful and useful pseudocode. Yes No. Not Helpful 21 Helpful How can I tell the difference between an odd and even number using pseudocode? Divide it by two to see if you get a remainder. If not, then it's even; if yes, then it's odd. Not Helpful 25 Helpful Since pseudocode isn't real code, there can't be any errors. You decide what you want to write as pseudocode and then translate it to any coding language you'd like.

Pseudocode Booklet PDF for GCSE Computer Science

Not Helpful 9 Helpful When you start jotting it down it can be anything from a notepad to a napkin or a dedicated writing application like Word or Google Docs. They can only interpret. You cannot run code with just raw text. Remember to make it a dev file first. Not Helpful 15 Helpful It isn't exactly necessary, but knowing pseudocode helps in learning how to program faster. Not Helpful 8 Helpful Not Helpful 38 Helpful Verbal works in this context: Can I use words such as "count" to sum up data in writing a pseudocode?

Foundations of Algorithms Using C++ Pseudocode

You can do whatever you like in pseudocode! Just as long as you know how to convert it to actual code, anything goes. Not Helpful 9 Helpful 7. Of course. You decide what you write in pseudocode. It won't come up with any errors and as long as you know how to code it into a programming language you should be fine.

Not Helpful 8 Helpful 5. Unanswered Questions. Answer this question Flag as Flag as What do I do to properly draw a flowchart when writing pseudocode?

Draw a detailed flowchart of a library system? Include your email address to get a message when this question is answered. Already answered Not a question Bad question Other. Tips Pseudocode is optimal for complex programs that are hundreds to thousands of lines in length. Warnings Pseudocode cannot be substituted for actual code when creating a program. Pseudocode can only be used to create a reference for what the code should do.

Edit Related wikiHows. Article Summary X 1. Did this summary help you? Article Info This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. Programming In other languages: Is this article up to date?

Cookies make wikiHow better. By continuing to use our site, you agree to our cookie policy. Co-Authored By:. April 8, Related Articles. Can you tell us which parts were out of date so we can update them? Thank you for your feedback!

Go to step 3 to get next Value 6. Output the sum 7.

In this algorithm, step 3 to 5 will be repeated, where a number is obtained and added to sum. Similarly the flowchart indicates a flowline being drawn back to the previous step indicating that the portion of the flowchart is being repeated. One problem indicates that these steps will be repeated endlessly, resulting in an endless algorithm or flowchart. The algorithm needs to be improved to eliminate this problem.

In order to solve this problem, we need to add a last value to the list of numbers given. This value should be unique so that, each time we get a value, we test the value to see if we have reached the last value. In this way our algorithm will be a finite algorithm which ends in a finite number of steps as shown below. There are many ways of making the algorithm finite.

The new list of numbers will be 26, 49, , , , 1, The value —1 is a unique number since all other numbers are positive. Get a value MT If the value is equal to —1, go to step 7 5.

Go to step 3 to get next Value 7. Output the sum 8.

DATA TYPES Although some contemporary languages allow programmers to invent his own data types, and define their related operations, there are a number of traditional data types found in most languages: Integer Integers are numeric data items, which are either positive or negative including zero, i. Some programming languages put restrictions on the magnitude of integers which may be used in program instructions.

These restrictions are usually dependent on the size of the memory location of the computer in which the language may run. Fixed Point Fixed point data items are numbers which have embedded decimal point i. Floating Point Floating point data items are numbers, which are, held as binary fractions by a computer.

The numbers are expressed in a form where you have a mantissa and an exponent, for example Number Mantissa Exponent Boolean Boolean data items are used as status indicators and may contain only one of two possible values: True or False. A constant is a specific value or character string used explicitly in an operation. Consider the constant values Multiply … by At any particular time, a variable will stand for one particular data, called the value of a variable, which may change from time to time during a computing process.

The value of a variable may change many times during the execution of a program. A variable is usually given a name by the programmer. Assignment The assignment operation has the form: Thus it is used whenever you need to keep track of a value that is needed later. Some typical uses include: The variable must be declared.

Variables used in the expression must be defined have values. The type of the expression must be compatible with the type of the variable. The order in which assignments are performed is important for example, if the first and second assignments in the swap sequence were interchanged, x and y would end up assigned to the same value.

The input operation and the output operation share some of the same constraints. Pseudocode is a generic way of describing an algorithm without use of any specific programming language syntax. It is, as the name suggests, pseudo code —it cannot be executed on a real computer, but it models and resembles real programming code, and is written at roughly the same level of detail.

Natural language is used whenever details are unimportant or distracting.

Since pseudocode style varies from author to author, there is usually an accompanying introduction explaining the syntax used. In the algorithm design, the steps of the algorithm are written in free English text and, although brevity is desired, they may be as long as needed to describe the particular operation.

File history

The steps of an algorithm are said to be written in pseudocode. Many languages, such as Pascal, have a syntax that is almost identical to pseudocode and hence make the transition from design to coding extremely easy. The following section deal with the control structures control constructs Sequence, Selection and Iteration or Repetition. These are illustrated below: The sequence structure The first type of control structures is called the sequence structure.

This structure is the most elementary structure. The sequence structure is a case where the steps in an algorithm are constructed in such a way that, no condition step is required. The sequence structure is the logical equivalent of a straight line. For example, suppose you are required to design an algorithm for finding the average of six numbers, and the sum of the numbers is given. This is the pseudo-code required to input three numbers from the keyboard and output the result.

Use variables: The following pseudo-code describes an algorithm which will accept two numbers from the keyboard and calculate the sum and product displaying the answer on the monitor screen. This structure can be illustrated in a flowchart as follows: Otherwise Task-A is executed. For example, there are occasions where we need to take action according to the user choice.

All computer languages provide a means of selection. Usually it is in the form of If statement and our pseudo-code is no exception to this. We will use the if statement together with logical operators to test for true or false as shown below.

The following shows how the selection control structure is used in a program where a user chooses the options for multiplying the numbers or adding them or subtracting.

Often there are conditions to be linked. In everyday language we say things like If I had the time and the money I would go on holiday. The and means that both conditions must be true before we take an action.

We might also say I am happy to go to the theatre or the cinema. The logical link this time is or. Conditions in if statements are linked in the same way. Conditions linked with and only result in an action when all conditions are true.

Conditions linked with an or lead to an action when either or both are true.

Example 6: The program is to input a examination mark and test it for the award of a grade. The mark is a whole number between 1 and Grades are awarded according to the following criteria: A more elegant set of conditions can be created by adding an else statement to the if statement. The else statement is used to deal with situations as shown in the following examples.

Example 7: A person is paid at top for category 1 work otherwise pay is at normal rate. If the work is category 1 pay-rate is top Else pay-rate is normal MT An alternative method provided in a number of languages is to use a selector determined by the alternative conditions that are needed. In our pseudo-code, this will called a case statement.

Navigation menu

Example 8: The following program segment outputs a message to the monitor screen describing the insurance available according to a category input by the user. Repetition or Iteration Structure A third structure causes the certain steps to be repeated. The commands used to create iterations or loops MT There three constructs for iterations or loops in our pseudo- code.

The Repeat Until loop. A program segment repeatedly asks for entry of a number in the range 1 to until a valid number is entered. A survey has been carried out to discover the most popular sport.

The results will be typed into the computer for analysis. Write a program to accomplish this. This type of conditional loop tests for terminating condition at the beginning of the loop. In this case no action is performed at all if the first test causes the terminating condition to evaluate as false. Write a program that will output the square root of any number input until the number input is zero.

In some cases, a variable has to be initialised before execution of the loop as shown in the following example. Use variable: This, in its simplest form, uses an initialisation of the variable as a starting point, a stop condition depending on the value of the variable. The variable is incremented on each iteration until it reaches the required value. The pseudo-code syntax will be: The loop variable can be used in any statement of the loop.

The variable should not be assigned a new value within the loop, which may change the behaviour of the loop. Example Write a program to calculate the sum and average of a series of numbers. The pseudo-code solution is: These three are the basic control structures out of which all programs are built. Beyond this, flowcharts serve the programmer in two distinct ways: Example Design an algorithm and the corresponding flowchart for finding the sum of n numbers.

We compare I with n to check whether we have exhausted the numbers or not in order to stop the computation of the sum or to stop the iteration structure. In such a case, I is referred to as a counter. Design an algorithm and the corresponding flowchart for finding the sum of the numbers 2, 4, 6, 8, …, n 2. Using flowcharts, write an algorithm to read numbers and then display the sum.

Write an algorithm to read two numbers then display the largest. Write an algorithm to read two numbers then display the smallest 5. Write an algorithm to read three numbers then display the largest.Explaining a computing process to less-technical users.


Write an algorithm to read two numbers then display the largest. This concept of problem solution and communication makes the study of algorithms important to computer science.

Floating Point Floating point data items are numbers, which are, held as binary fractions by a computer. When you start jotting it down it can be anything from a notepad to a napkin or a dedicated writing application like Word or Google Docs. Conditions in if statements are linked in the same way. Tips Pseudocode is optimal for complex programs that are hundreds to thousands of lines in length. Pseudocode is used to show how a computing algorithm should work.

Learn more. Find sources: