程序通过定义学生结构体变量，存储了学生的学号、姓名和3门课的成绩。所有学生数据均以二进制方式输出到文件中。函数fun()的功能是从形参filename所指的文件中读入学生数据，并按照学号从小到大排序，再用二进制方式把排序后的学生数据输出到filename所指的文件中，覆盖原来的文件内容。
请在程序的下划线处填入正确的内容并把下划线删除，使程序得出正确的结果。
#include＜stdio.h＞
#define N 5
typedef struct student
long sno;
char name[10];
float score[3];
STU;
void fun(char *filename)
FILE *fp;int i,j;
STU s[N],t;
/**********found**********/
fp=fopen(filename, (1) );
fread(s,sizeof(STU),N,fp);
fclose(fp);
for(i=0;i＜N-1;i++)
for(j=i+1;j＜N;j++)
/**********found**********/
if(s[i].sno (2) s[j].sno)
t=s[i];s[i]=s[j];s[j]=t;)
fp=fopen(filename,"wb");
/**********found**********/
(3) (s,sizeof(STU),N,fp);/*二进制输出*/
fclose(fp);
main()
STUt[N]=10005,"ZhangSan",95,80,88,10003,"LiSi",85,70,78,10002,"CaoKai",75,60,88,10004,"FangFang",
90,82,87,10001,"MaChao",91,92,77,SS[N];
int i,j;FILE *fp;
fp=fopen("student.dat","wb");
fwrite(t,sizeof(STU),5,fp);
fclose(fp);
printf("\n\nThe original data:\n\n");
for(j=0;j＜N;j++)
printf("\nNo:%ld Name:%-8s Scores:",t[j].sno,t[j]name);
for(i=0;i＜3;i++)printf("%6.2f",t[j]score[i]);
printf("\n");
fun("student.dat");
printf("\n\nThe data after sorting:\n\n");
fp=fopen("student.dat","rb");
fread(ss,sizeof(STU),5,fp);
fclose(fp);
for(j=0;j＜N;j++)
printf("\nNo:%ld Name:%-8s Scores:",ss[j].sno,ss[j].name);
for(i=0;i＜3;i++)printf("%6.2f",ss[j].score[i]);
printf("\n");