学生成绩管理系统

#include 
#include 
typedef struct
{
    int studentID;
    char studentname;
    int score[3];
}STUDENT;
int cf(STUDENT a[],STUDENT num[]);
int chazhao(STUDENT num[],long x,int n);
int paixu(STUDENT a[],STUDENT num[],int n);
int aver(STUDENT a[],int n);
int swap(int *x,int *y);
int main()
{
  int n,flat;
  STUDENT a[100];
  STUDENT num[100];
  long x;
   n=cf(a,num);
   aver(a,n);
   paixu(a,num,n);
   printf("输入你想要查找的学生学号:");
   scanf("%ld",&x);
   flat=chazhao(num,x,n);
   if(flat!=-1)
   {
       printf("输入成绩%d\n",a[flat].score[flat]);
   }
   else
    printf("没有找到");

   return 0;
}
int cf(STUDENT a[],STUDENT num[])
{
    int i=-1;
    do
    {
        i++;
        printf("输入学生的成绩和学号,姓名:\n");
       scanf("%d%d%s",&a[i].score[i],&num[i].studentID,&a[i].studentname);
    }while(a[i].score[i]>=0&&num[i].studentID>=0);
      return i;
}
int chazhao(STUDENT num[],long x,int n)
{
    int i;
    for(i=0;iif(num[i].studentID==x)
            return i;
    }
    return -1;

}
int paixu(STUDENT a[],STUDENT num[],int n)
{
    int i,j,k;
    for(i=0;i1;i++)
    {
        k=i;
        for(j=i+1;jif(a[i].score[i]if(k!=i)
        {
            swap(&a[k].score[k],&a[i].score[k]);
            swap(&num[k].studentID,&a[i].studentID);
        }
    }
}
int aver(STUDENT a[],int n)
{
    int i;
    float sum=0,cj;
    for(i=0;iprintf("%f\n",cj);
}
int swap(int *x,int *y)
{
    int cf;
    cf=*x;
    *x=*y;
    *y=cf;
}

程序存在问题，有待修改。