下面代码运行没有问题。
#include <stdio.h>
int main()
{
int n;
double score;
double average = 0.0;
int above_90=0, above_80=0, above_70=0, above_60=0, fail=0;
scanf("%d", &n);
for (int i=0; i<n; i++)
{
scanf("%lf", &score);
average += score;
if (score >= 90)
++above_90;
else if (score >= 80)
++above_80;
else if (score >= 70)
++above_70;
else if (score >= 60)
++above_60;
else
++fail;
}
average /= n;
printf("%.11f %d %d %d %d %d\n", average, above_90, above_80, above_70, above_60, fail);
return 0;
}