有序链表合并排序

//合并排序函数1
#include"stdlib.h"
typedef struct code
{
    int data;
    struct code *next;
}Code;

Code *Insert(Code *head1,Code *head2)
{
    Code *head,*cur;
    if(head1==NULL)
        return head2;
    if(head2==NULL)
        return head1;
    if(head1->data>head2->data)//找出最小的data;
    {
        head=head2;
        head2=head2->next;
    }
    else
    {
        head=head1;
        head1=head1->next;
    }
    for(cur=head;head1!=NULL&&head2!=NULL;)
    {
        if(head1->data<head2->data)
        {
            cur->next=head1;
            cur=head1;
            head1=head1->next;
        }
        else
        {
            cur->next=head2;
            cur=head2;
            head2=head2->next;
        }
    }
    cur->next=(head1==NULL?head2:head1);//head1和head2至少有一个为空时，剩下的那个链表直接放在cur->next.
    return head;
}

//合并排序函数2
#include"stdlib.h"
typedef struct code
{
    int data;
    struct code *next;
}Code;

Code *Insert(Code *ahead,Code *bhead)
{
    Code *pa1,*pa2,*pb1,*pb2;
    pa1=pa2=ahead;
    pb1=pb2=bhead;
    do //让b链表中的结点依次和a链表的结点比较并插入；
    {
        while((pb1->data>pa1->data)&&(pa1->next!=NULL))
        {
            pa2=pa1;
            pa1=pa1->next;
        }
        if(pb1->data<=pa1->data)
        {
            if(pa1==ahead)
                ahead=pb1;
            else
                pa2->next=pb1;
            pb1=pb1->next;
            pb2->next=pa1;
            pa2=pb2;
            pb2=pb1;
        }
    }while(pa1->next!=NULL);
    if(pa1==NULL)
        pa1->next=pb1;
    return ahead;
}