双端链表 冒泡排序 有头结点

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

typedef char * ElemType;

typedef struct DuLNode {
    ElemType data;
    struct DuLNode *prior, *next;
} DuLNode, *DuLinkList;


DuLinkList create(){
    return (DuLinkList)malloc(sizeof(DuLNode));
}

char * create_str(char *str){
    char *ss = (char *)malloc((strlen(str) + 1) * sizeof(char));
    strcpy(ss, str);
    return ss;
}

void scan(DuLinkList L){
    int n;
    char str[1024];
    DuLinkList lp, p = L;
    scanf("%d", &n);
    while(n--){
        scanf("%s", str);

        lp = create();
        lp->data = create_str(str);
        lp->prior = p;
        lp->next = NULL;

        p->next = lp;

        p = lp;
    }
}
void insertion_sort(DuLinkList L){
    
    DuLinkList sign = NULL, p1, p2, p = L->next;
    for(DuLinkList cnt = p; cnt->next != NULL; cnt = cnt->next){
        for(p1 = p, p2 = p->next; p2 != sign; p1 = p1->next, p2 = p2->next){
            if(strcmp(p1->data, p2->data) >= 0){
                char *tmp = p1->data;
                p1->data = p2->data;
                p2->data = tmp;
            }
        }
        sign = p1;
    }
}

void print(DuLinkList L){
    DuLinkList p = L->next;
    while(p != NULL){
        printf("%s ", p->data);
        p = p->next;
    }
    puts("");
}

int main(){
    //freopen("data.txt", "r", stdin);
    DuLNode L;
    //输入数据
    scan(&L);
    //打印输出
    print(&L);
    //冒泡排序
    insertion_sort(&L);
    //打印数据
    print(&L);

    return 0;
}