数据结构c语言学生成绩管理系统

 ######求讲解这段代码！！

typedef struct student ElemType;
 //顺序表 
 typedef struct
 {
     ElemType *elem; // 存储空间的基地址 
     int length; // 当前长度 
 }SqList;
 Status merge_sq(SqList *L,SqList *L3); 
 Status InitList(SqList *L) // 构造空的顺序表 L 
 {    
     L->elem=(ElemType *)malloc(sizeof(ElemType)*100);
     if(!L->elem)  exit(OVERFLOW);
     L->length=0;
     return OK;
 } 
 //将txt1,2中的数据传到顺序表中 
 Status merge_sq(SqList *L,SqList *L3) 
 {
 
     FILE *fp;
     //把txt1内容输到数组s[3] 
     int i,k;
     p=s;
     if((fp=fopen(str1,"rt"))==NULL)
     {
         printf("cannot open this file");
         exit(0);
     }
     for(i=0;!feof(fp);i++,p++)
     fscanf(fp,"%s    %s    %d    %d    %d    %d\n",&p->name,&p->num,&p->chinese,&p->math,&p->English,&p->total);
     fclose(fp);
     //把txt2内容输到数组r[3] 
     int j,n,m;
     q=r;
     if((fp=fopen(str2,"rt"))==NULL)
     {
         printf("cannot open this file");
         
         exit(0);
     }
     for(n=0;!feof(fp);n++,q++)
     fscanf(fp,"%s    %s    %d    %d    %d    %d\n",&q->name,&q->num,&q->chinese,&q->math,&q->English,&q->total);
     fclose(fp);
 //数组s[3]，r[MAXSIZE]合并到数组c[MAXSIZE]    
    for(j=0;jfor(int l=0,j=i;jfor(j=0;jelem[j+1]=c[j];
     L->length=j+1;
    for(j=0;jelem[j+1]=c[j];    
     L3->length=j+1; 
     return OK;  
 }