程序错误，看下那里有错。

＃include
float fun_ave (int a1,int b2,int c3,int d,int e) ;
void main ()
{
int (a,b,c,d,e);
float ave;
printf ("input 5 digits\n") ;
scanf ("%a%b%c%d%e", &a, &b, &c, &d, &e) ;
ave=fun_ave(a,b,c,d,e);
printf("平均分为％f\n",ave);
}
float fun_ave(int a1,int b2, int c3,int d,int e)
{
float average;
average= (a1+b2+c3+d+e) *1. 0/5;
return average;
}

int (a,b,c,d,e);括号去掉
这些全是%d

#include <stdio.h>
float fun_ave (int a1,int b2,int c3,int d,int e) ;
void  main ()
{
int a,b,c,d,e;
float ave;
printf ("input 5 digits\n") ;
scanf ("%d%d%d%d%d", &a, &b, &c, &d, &e) ;
ave=fun_ave(a,b,c,d,e);
printf("平均分为%f\n",ave);
 
}
float fun_ave(int a1,int b2, int c3,int d,int e)
{
float average;
average= (a1+b2+c3+d+e) *1.0/5;
return average;
}