欢迎使用CSDN-markdown编辑器

#include<stdio.h>
int main(void)
{
int count,num;
double grade,total;

num=0;
total=0;
count=0;
printf("Enter grades:");
scanf("%lf",&grade);
while(grade>=0)
{
total=total+grade;
num++;
if(grade<60)
{
count++;
}
scanf("%lf",&grade);
}
if(num!=0)
{
printf("Grade average is %.2f\n",total/num);
printf("Number of failures is %d\n",count);
}
else
{
printf("Grade average is 0\n");
}
return 0;

}