求两个数的乘积和商数，该作用由宏定义来实现。

解：  #include <stdio.h>

main()

#define product(a,b) (a*b)

#define divide(a,b)  (a/b)

{

  float result,n1,n2;

  printf(“input n1:”);

  scanf(“%f”,&n1);

printf(“input n2:”);

scanf(“%f”,&n2);

result=product(n1,n2);

printf(“%fn”,result);

result=divide(n1,n2);

printf(“%f/n”,result);

}