双向链表的简单实现

#include<iostream>
#include<ctime>
using namespace std;

struct list
{
    int number;
    list *prior;
    list *next;
};


int FindLinkList(list *t, int i)
{
    if (!t)
        return -1;
    int j = 0;
    list *p = t;
    for (; j < i; j++)
    {
        p = p->next;
        if (p == t)
            return -1;
    }
    return p->number;
}


void addlinklist(list *t, int i)
{
    int j = 0;
    list *p = t;
    list *s;
    while (p&&j < i)
    {
        p = p->next;
        j++;
    }
    if (p)
    {
        s = new list;
        s->number = i;
        s->prior = p;
        s->next = p->next;
        p->next = s;
        if (p->next)
        {
            p->next->prior = s;
        }
    }
}



int deletelinklist(list *t, int i)
{
    list *p=t;
    int j = 0;
    for (; j < i; j++)
    {
        p = p->next;
        if (p == t)
            return -1;
    }
    p->prior->next = p->next;
    p->next->prior = p->prior;
    j = p->number;
    delete p;
    return j;
}

void createlinklist(list *t, int i)
{
    srand(time(0));
    list *p;
    for (int j = 1; j <= i; j++)
    {
        p = new list;
        p->number = rand() % 100 + 1;
        //cout << p->number << endl;
        p->prior = t;
        p->next = t->next;
        t->next->prior = p;
        t->next = p;
    }

}


void main()
{
    list *linklist=new list;
    linklist->next = linklist;
    linklist->prior = linklist;
    linklist->number = 10;
    createlinklist(linklist, 10);
    for (int i = 1; i <= 10; i++)
        cout << FindLinkList(linklist, i) << endl;
    deletelinklist(linklist, 2);
    cout << endl;
    for (int i = 1; i <= 9; i++)
        cout << FindLinkList(linklist, i) << endl;
}