Design And Analysis of Algorithms

Definition:
An algorithm is a finite set of instructions that, if followed, accomplishes a particular task.
In addition, all algorithms must satisfy the following criteria:
• Input. Zero or more quantities are externally supplied.
• Output. At least one quantity is produced.
• Definiteness. Each instruction is clear and unambiguous.
• Finiteness. The algorithm terminates after a finite number of steps.
• Effectiveness. Every instruction must be very basic enough and must be feasible.

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Algorithm Definition: 

• An algorithm is a sequence of unambiguous instructions for solving a problem, i.e., for obtaining a required output for any legitimate input in a finite amount of time. 

• Algorithms that are definite and effective are also called computational procedures.

 • A program is the expression of an algorithm in a programming language.

We can describe an algorithm in many ways.

 1. Natural language: use a natural language like English

 2.Flow charts: Graphic representations called flowcharts, only if the algorithm is small and simple. 3.Pseudo-code: also avoids most issues of ambiguity; no particularity on syntax programming language

What is Algorithm Specification:
Comments begin with // and continue until the end of line.
2. Blocks are indented with matching braces {&}.Compound statement can be  represented as a block.statements delimted by ;
3.identifier begins with a letter.
   The data types of variables whether it is local or global based on context.
   compound data types can be formed with records.
node=record
   {
            datatype_1 data1;
            datatype_n   datan;
            node *link;
   }

4.Assignment of values to variables done using assignment statement;
<variable>:=<expression>;
 

}