程序代码：

#include <stdio.h>

int main(void) {
    float fahr, celsius;
    int lower, upper, step;

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

    printf("C     F\n\n");
    celsius = lower;

    while(celsius <= upper) {

         fahr = (9.0/5.0) * celsius + 32.0;
         printf("%3.0f %6.1f\n", celsius, fahr);
         celsius = celsius + step;
    }
    return 0;
}