單向鏈表

單向鏈表模版代碼：

功能：
1、建立鏈表（2種）
2、按成績高低插入某學生成績
3、刪除某個作弊學生的成績
4、展示所有學生的成績

#include <iostream>    
using namespace std;

typedef struct student {
    int id;
    float score;
    struct student *next;
}stu, *stull;

void createtail(stull &head,int n){//尾插法
    stull tail;
    head = (struct student *)malloc(sizeof(stu));
    head -> next = NULL;
    tail = head;
    for(int i=0; i<n; i++){
        stull p;
        p = (struct student *)malloc(sizeof(stu));
        cout<<"輸入學生ID:"<<endl;
        cin>> p->id;
        cout<<"輸入學生成績:"<<endl;
        cin>> p-> score;
        if(head -> next == NULL){
            head -> next = p;
            p -> next = NULL;
            tail = p;
        }
        else{
            tail -> next = p;
            p -> next = NULL;
            tail = p;    //注意tail的指向問題
        }
    }
}
/*當頭指針爲空時將頭指針指向p，p指向NULL，尾指針指向p
      當頭指針不爲空時，尾指針指向p，p指向NULL，tail指向p。 */

void createhead(stull &head,int n){//頭插法
    stull p;
    head = (struct student *)malloc(sizeof(stu));
    head -> next = NULL;
    for(int i = 0; i<n; i++){
        p=(struct student *)malloc(sizeof(stu));
        cout<<"輸入學生ID:"<<endl;
        cin>> p -> id;
        cout<<"輸入學生成績:"<<endl;
        cin>> p -> score;
        if( head->next == NULL){
            head -> next = p;
            p -> next = NULL;
        }
        else{
            p -> next = head -> next;
            head -> next = p;
           // p -> next=NULL;
        }
    }
}
/*當頭指針爲空，將頭指針指向p，p指向NULL
  當頭指針不爲空時，將p指向首源節點，將頭指針指向p*/

void init(stull &head){//插入功能 不是初始化、、、
    stull p;
    p=(struct student *)malloc(sizeof(stu));
    cout<<"插入學生ID:"<<endl;
    cin >> p -> id;
    cout<<"插入學生成績"<<endl;
    cin >> p -> score;
    stull t;
    t=head;
    for( ;t;t=t->next ){
        if( t -> next->score > p->score && t->score < p->score){
            p -> next = t->next;
            t -> next = p;
            break;
        }
    }
}

void delet(stull &head,int id){ //刪除id的節點
    stull t;
    t=head;
    for(; t;t=t -> next){
        if(t -> next -> id==id){
            stull temp;
            temp=t -> next;
            t -> next = temp -> next;
            free(temp);
            break;
        }
    }
}

void display(stull &head){//展示功能
    stull t;
    t=head -> next;
    while(t!=NULL){
        cout<<"ID:"<< t->id <<endl;
        cout << "score:" << t -> score << endl;
        t = t -> next;
    }
}
int main() {
    stull head;
    head=(struct student *)malloc(sizeof(stu));
    int n;
    cout<<"學生數目:"<<endl;
    cin>>n;
    createhead(head,n);
    display(head);
    int k;
    cout<<"輸入作弊學生ID:"<<endl;
    cin>>k;
    delet(head,k);
    display(head);
    init(head);
    display(head);

    return 0;
}