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;
 }
}