### What is a Program?

A program is a sequence of instructions (called programming statements), executing one after another - usually in a sequential manner, as illustrated in the following flow chart Figure 1.

Figure 1 Flow Chart

### What is Algorithm?

An algorithm is a finite set of instructions or logic, written in order, to accomplish a certain predefined task. Algorithm is not the complete code or program, it is just the core logic (solution) of a problem, which can be expressed either as an informal high level description as pseudocode or using a flowchart

### Steps in the development of Algorithm?

Problem definition

Development of a model

Specification of Algorithm

Designing an Algorithm

Checking the correctness of Algorithm

Analysis of Algorithm

Implementation of Algorithm

Program testing

Documentation Preparation

Every Algorithm must satisfy the following properties

Input- There should be 0 or more inputs supplied externally to the algorithm.

Output- There should be at least 1 output obtained.

Definiteness- Every step of the algorithm should be clear and well defined.

Finiteness- The algorithm should have finite number of steps.

Correctness- Every step of the algorithm must generate a correct output.

** Don’t miss the Key Requirements

### What are the symbols used Algorithm?

Figure 2 Following Symbols we can user in making Algorithms

### How to use Flowcharts to Represent Algorithms

Figure 3 Example of representation

### If-Then

### If-Then-else

### Loop

### Basic Arithmetic Operations

Operator | Meaning | Example |

+ | Addition | x + y |

- | Subtraction | x - y |

* | Multiplication | x * y |

/ | Division | x / y |

% | Modulus (Remainder) | x % y |

++ | Increment by 1 (Unary) | ++x or x++ |

-- | Decrement by 1 (Unary) | --x or x-- |

&& | Logical AND | (x >= 1) && (x <= 100) |

|| | Logical OR | (x < 1) || (x > 100) |

! | Logical NOT | !(x == 8) |