单链表以排序方式插入

#include <stdio.h>
#include <stdlib.h>

struct list_data
{
    int data;
    struct list_data *next;
};

struct list_data *head;
int first_flag = 0;

void insert_data(int data)
{
    struct list_data* d_list;
    struct list_data *p,*q;

    if(first_flag == 0)
    {
        head->data = data;
        first_flag = 1;
        return;
    }

    d_list = (struct list_data*)malloc(sizeof(struct list_data));
    d_list->data = data;

    p = head;
    q = head->next;
    if(p->data >= data)
    {
        d_list->next = p;
        head = d_list;
        return;
    }
    if(q == NULL)
    {
        p->next = d_list;
        return;
    }

    while(q)
    {
        if(q->data >= data)
        {
            p->next = d_list;
            d_list->next = q;
            break;
        }
        else
        {
            p = p->next;
            q = q->next;
            if(q == NULL)
            {
                p->next = d_list;
                break;
            }
        }

    }

}

int main(int argc, char *argv[])
{
    struct list_data *p;
    int i,a[256],num;
    head = (struct list_data*)malloc(sizeof(struct list_data));

    insert_data(34);
    insert_data(13);
    insert_data(22);
    insert_data(1);
    insert_data(1);
    insert_data(26);
    insert_data(62);
    insert_data(7);
    insert_data(7);

    p = head;
    i = 0;
    while(p)
    {
        a[i++] = p->data;
        p = p->next;
    }
    num = i;
    for(i=0;i<num;i++)
        printf("%d,",a[i]);
    printf("\n");

    return 0;
}