17：C语言之C循环-求平均成绩

#include<>
int main(void)
{  
 	 /*********Begin*********/
	int a,i;
	double b,c=0;
	scanf("%d",&a);
	if(a<=0)
	{
		printf("the number of students: the scores:average=0.00\n");
	}
	else
	{
		for(i=1;i<=a;i++)
		{
			scanf("%lf" ,&b);
			c=c+b;
		}
	printf("the number of students: the scores:average=%.2f\n",c/a);
	}
	  /*********End**********/ 
	return 0;
}