利用函数求平均数的程序为什么结果全为0?

利用函数求平均数的程序为什么结果全为0?
#include
float a1[10];
int a[10][5]={1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50};
int main()
{
x09void aver();
x09aver();
x09return 0;
}
void aver()
{
x09int i,j;
x09for(i=0;i