void main(void)
{
int count = 0; //输入成绩个数
int sum = 0; //总分
float ave = 0; //平均分
int score;
scanf("%d", &score);
while(score != -1)
{
count ++;
sum += score;
scanf("%d", &score);
}
if(count == 0)
printf("没有输入学生成绩\n");
else{
ave = (float)sum / count;
printf("平均分: %.1f\n", ave);
}
}