Logic Resistance Calculator in C++

Author: George Wanis Ayed Wanis
Student ID: 2300280
Project: C++ Programming Project

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Overview

This program calculates the total electrical resistance of a circuit that contains resistors connected in series and parallel.
The user provides a single input string that describes the circuit, and the program evaluates it step by step until the final equivalent resistance is obtained.

The program supports:

• Series operations using S or s
• Parallel operations using P or p
• End of operation using E or e

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Input Format

You must enter the circuit description as a single line.

Rules

• Use S (or s) for series group
• Use P (or p) for parallel group
• End each group with E (or e)
• Separate resistor values using spaces or commas
• Only numbers, S, P, E, spaces, commas and dots are allowed
• Any other character will result in "Wrong Description"

Examples

S 10 20 E

Means: 10Ω and 20Ω in series

P 10 20 30 E

Means: 10Ω, 20Ω, 30Ω in parallel

Nested example: S 10 P 20 30 E 40 E

Means: 10Ω in series with (20Ω || 30Ω) in series with 40Ω

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How the Program Works

1. The program first checks the input for invalid characters.
   If something invalid is found, it prints: Wrong Description

2. It repeatedly finds the last S or P in the string.

3. It finds the matching E after it.

4. It extracts the numbers between them.

5. It calculates:

• Series:
  R = R1 + R2 + ...
• Parallel:
  R = 1 / (1/R1 + 1/R2 + ...)

6. It replaces the whole operation with the computed equivalent value.
7. This continues until no S or P remain.

Finally, it prints: The total resistance =

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Compilation and Run

Compile: bash g++ -o resistance main.cpp Run:

./resistance Then paste your circuit description and press Enter.

Example Runs Input:

S 10 20 30 E Output:

The total resistance = 60 Input:

P 10 20 30 E Output:

The total resistance = 5.45455 Input:

S 10 P 20 30 E 40 E Output:

The total resistance = 50 Important Notes Series must contain at least 2 resistors, otherwise:

Incorrect Input Parallel must contain at least 3 resistors, otherwise:

Incorrect Input The program supports nested operations naturally

Input must strictly follow the described format

License This project was created for educational purposes as part of a university assignment.

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