Integer Basics

Some examples of basic arithmetic in C.

Convert fahrenheit to celsius

#include <stdio.h>
/* print Fahrenheit-Celsius table
for fahr = 0, 20, ..., 300; floating-point version */

int main() {
  printf("FAHRENHEIT -> CELSIUS\n");
  float fahr, celsius;
  float lower, upper, step;

  lower = 0;
  upper = 300;
  step = 20;

  fahr = lower;
  while (fahr <= upper) {
    celsius = (5.0/9.0) * (fahr - 32.0);

    printf("\t %3.0f %6.1f\n", fahr, celsius);
    fahr = fahr + step;
  }
  
}

Convert celsius to fahrenheit

#include <stdio.h>
/* print Fahrenheit-Celsius table
for fahr = 0, 20, ..., 300; floating-point version */

#define UPPER 300
#define LOWER 0
#define STEP 20


int main() {
  printf("CELSIUS -> FAHRENHEIT\n");
  float fahr, celsius;

  for (celsius = LOWER; celsius <= UPPER; celsius = celsius + STEP) {
    fahr = (celsius * (9.0/5.0)) + 32.0;
    printf("\t %3.0f %6.1f\n", celsius, fahr);
  }  
  float thelow = (33 * (9.0/5.0)) + 32.0;
  float thehigh = (37 * (9.0/5.0)) + 32.0;

  printf("%6.1f %6.1f\n", thelow, thehigh);

}