一个链表程序，支持建立，插入，删除，输出；学生的学号和分数

#include <iostream.h> #include <malloc.h> #define NULL 0 #define LEN sizeof(struct stu) #define BY (struct stu *)malloc(LEN) typedef struct stu STU; struct stu { long int num; float score; struct stu *next; }; int n; struct stu *creat()//建立链表 { struct stu *p2,*p1,*head; n=0; p1=p2=BY; cin>>p1->num>>p1->score; head=NULL; for(;p1->num!=NULL;) { n+=1; if(n==1) head=p1; else p2->next=p1; p2=p1; p1=BY; cin>>p1->num>>p1->score; } p2->next=NULL; return head; } void print(struct stu *head)//查询链表 { struct stu *p; cout<<"putout the students' number and score:/n"; p=head; for(;p!=NULL;) { cout<<"number:"<<p->num<<"/tscore:"<<p->score<<endl; p=p->next; } } STU *insert(STU *head,STU *std)//插入链表 { STU *p0,*p1,*p2; p1=head; p0=std; if(head==NULL) { head=p0; p0->next=NULL; } else { while((p0->num>p1->num)&&(p1->next!=NULL)) { p2=p1; p1=p1->next; } if(p0->num<=p1->num) { if(head==p1)head=p0; else p2->next=p0; p0->next=p1; } else { p1->next=p0; p0->next=NULL; } } n+=1; return head; } STU *dele(STU *head,long int num)//删除链表 { STU *p1,*p2; if(head==NULL) {cout<<"empty list!/n";goto end;} p1=head; while(p1->num!=num&&p1->next!=NULL) {p2=p1;p1=p1->next;} if(p1->num==num) {if(p1==head)head=p1->next; else p2->next=p1->next; n=n-1; free(p1); } else cout<<"the node not been found!/n"; end: return head; } int main(int argc, char* argv[]) { struct stu *cl,*stud; long int num; int i; cout<<"*************************************************/n" <<endl <<"selet the item *****/n" <<"1:set the students' resoure *****/n" <<"2:query the students' resoure *****/n" <<"3:insert the students' resoure *****/n" <<"4:delete the students' resoure *****/n" <<"0:ESC the program! *****/n" <<endl <<"************************************************/n"; do { cout<<"select the number to next/n"; cin>>i; switch(i) { case 1: { cout<<"Please input the students' number and score:"<<endl <<"number/tscore"<<endl; cl=creat(); }break; case 2: { cout<<"number/tscore"<<endl; print(cl); }break; case 4: { cout<<"input the delete number:/n"; cin>>num; cl=dele(cl,num); }break; case 3: { cout<<"input the insert number and score:/n"; stud=BY; cin>>stud->num>>stud->score; cl=insert(cl,stud); }break; case 0: break; default:cout<<"input err/n";break; } }while(i!=0); return 0; }