careercup-链表 2.1

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

struct ListNode
{
    int val;
    ListNode *next;
    ListNode(int x):val(x),next(NULL) {}
};

void createList(ListNode *&L)
{
    int arr[10]= {1,2,3,2,5,6,7,3,9,1};
    int i;
    ListNode *p=NULL;
    for(i=0; i<10; i++)
    {
        ListNode *tmp=new ListNode(arr[i]);
        if(L==NULL)
        {
            L=tmp;
            p=tmp;
        }
        else
        {
            p->next=tmp;
            p=tmp;
        }
    }
}

void deleteDup(ListNode *L)
{
    if(L==NULL)
        return;
    ListNode *p=L;
    ListNode *q=NULL;
    ListNode *qpre=NULL;
    ListNode *tmp=NULL;
    while(p)
    {
        if(p->next)
        {
            if(p->val==p->next->val)
            {
                tmp=p->next;
                p->next=tmp->next;
                tmp->next=NULL;
                delete(tmp);
                continue;
            }
            else
                q=p->next;
        }
        while(q)
        {
            if(q->val==p->val)
            {
                tmp=q;
                q=q->next;
                tmp->next=NULL;
                qpre->next=q;
                delete(tmp);
            }
            if(q)
            {
                qpre=q;
                q=q->next;
            }
        }
        p=p->next;
    }
}

int main()
{
    ListNode *head=NULL;
    createList(head);
    ListNode *p=head;
    while(p)
    {
        cout<<p->val<<" ";
        p=p->next;
    }
    cout<<endl;
    deleteDup(head);
    p=head;
    while(p)
    {
        cout<<p->val<<" ";
        p=p->next;
    }
    cout<<endl;
}