以逆序打印温度转换表

 #include <stdio.h>

#define LOWER 0.

#define STEP 20.

#define UPPER 300.

main(){

 double a=UPPER;

 while (a >= LOWER){

  printf("%6.2f\t%6.2f\n", a, (9 * a / 5 + 32));

  a = a - STEP;

 }

}