# C++ > Algorithms Code Examples

## Fahrenheit-Celsius converter

``` Fahrenheit-Celsius converter #include <iostream.h> #include <iomanip.h> #include <stdlib.h> void c_to_f(void); void f_to_c(void); void main(void) { int choice; char again; do { system("CLS"); cout << setw(10) <<" "<< "What conversion would you like to make?\n"; // menu cout << setw(20) <<" "<< "1. Celsius to Fahrenheit\n\n"; // make a choice which function to use. cout << setw(20) <<" "<< "2. Fahrenheit to celsius\n\n"; cin >> choice; switch(choice) // go to chosen function. { case 1 : { c_to_f(); break; } case 2 : { f_to_c(); break; } default : { cout << setw(10) <<" "<< "you must enter 1 or 2 "<< endl ; // validate and correct input of function choice. } } cout << setw(10) <<" "<< "Do you wish to do another conversion? y for yes, n for no "; // rerun loop on y for yes cin >> again; }while (again == 'Y' || again =='y'); } void c_to_f(void) { system("CLS"); // clear screen for function data. int temp,fahrenheit; cout << "\n\n\n"; cout << setw(10) <<" "<< "Enter the temperature in whole degrees celsius. \a"; cin >> temp; fahrenheit = ((temp * 9) / 5) + 32; cout << endl << setw(10) <<" "<< temp << " degrees celsius is " << fahrenheit << " degrees fahrenheit \a\n\n\n"; } void f_to_c(void) { system("CLS"); // clear screen for function data. int temp,celsius; cout << "\n\n\n"; cout << setw(10) <<" "<< "Enter the temperature in whole degrees fahrenheit. \a"; cin >> temp; celsius = ((temp - 32) * 5) / 9; cout << endl <<setw(10) <<" "<< temp << " degrees fahrenheit is " << celsius << " degrees celsius \a\n\n\n"; } ```