The document defines and describes the key elements of an algorithm, including that an algorithm is a set of instructions to perform a task, and that it must be well-ordered, unambiguous, effective, computable, executable, and halt in a finite time. It then outlines the common elements of algorithms, such as constants, variables, arrays, operators, loops, conditional statements, and comments.

1. Algorithm
By Taimoor Abdullah Khan
BSCS - 1st

2. Definition
“Set of instructions used to perform a certain task.”

3. Characteristics of an Algorithm
• Well-ordered Collection.
• Unambiguous.
• Effective.
• Computable Operations.
• Executable.
• Result giving.
• Halts in Finite amount of time.

4. Elements of Algorithm
1. Constants.
2. Variables.
3. Arrays.
4. Operators.
5. Loops.
6. Conditional Statements.
7. Comments

5. 1. Constants
• Numbers as same as in mathematics.
• Helps Structuring
Example: y = 5*c
i=i+1

6. Value
2. Variables
• For Storing Values.
• Can be given any name, but given such to
remind of its purpose. Sum, Temp etc.

7. Value Value Value
myArray
myArray
3. Arrays 0 1 2
• Two or more Variables with same name.
• Addressed individually by their index.
myArray[7]
• Variable or constant both used to address the
index.
• Each location can store a different value.
• Usually Starting at index 0.

8. 4. Operators
• Used to perform Operations on Variables or
Constants.
• Mathematical Operators: +, -, *, / and %.
• Assignment Operator: =
• Comparison Operator: ==
• Increment , Decrement Operator: ++, --

9. 5. Iteration
• Used to repeat a certain code or lines.
• Useful for replacing repetition.
• Can use Index variables for Arrays.
• Major two types of loops: for loop
While loop
• Can be stopped from inside off loop body by using
break; statement.

10. While Loop
• Repeats if a certain Condition is true.
• Stops when Condition becomes false.
• Can repeat Infinite times.
• Can be given value ‘1’ to represent Boolean value for ‘True’ so the loop
remains true.
• Syntax: while(Condition)
{
Loop body;
}

11. For Loop
• Given a Variable, for which the condition is set.
• Variable is Incremented or Decremented.
• Repeats for fixed amount of times.
• Syntax: for( i = 0; i <= n; i++) //n is any number
{
Loop body;
}

12. 6. Conditional Statement
• Used to take decision.
• Checks a Condition.
• Runs a statement body if Condition is true.
• Otherwise runs statment body for “Else” statement if any is given.
• Syntax: If(Condition)
{
Loop body;
}
Else
{
Loop body;
}

13. 7. Comments
• Useful in long and complex programs.
• Can be written where required
explanation.
• Mostly written after ‘//’.

14. The End
What Are You Staring At?? Its Done!

15. Thank you.