关于c:带头结点链表的基本操作

#include <stdio.h>#include <stdlib.h>#define INIT_LEN 6typedef struct node{    int x;    struct node * next;}link;link * initLink(link * head){    link * pr = head, *p;    int i, num;    printf("输出数组%d个元素的值。\n", INIT_LEN);    for(i = 0;i < INIT_LEN;i++){        //create node        p = (link*)malloc(sizeof(link));        if(p == NULL) exit(EXIT_FAILURE);        scanf("%d", &num);        p->x = num;        p->next = NULL;                //link node        pr->next = p;        pr = p;    }    return head;}link * deleteLink(link * head, int num){    link * p = head->next, *pr = head;    while(p != NULL){ //带头结点的删除        if(p->x == num) break;        pr = p;        p = p->next;    }        if(p == NULL){        printf("NOT FOUND!\n");    }else{        pr->next = p->next;        p->next = NULL;        free(p);    }        return head;}link * insertLink(link * head, int num){// 带头结点的程序插入    //create node    link * pt = (link*)malloc(sizeof(link));    if(pt == NULL) exit(EXIT_FAILURE);    pt->x = num;    pt->next = NULL;        if(head == NULL) head = pt;        link * p = head;    while(p->next != NULL && p->next->x < num)        p = p->next;        //when p->next->x >= num    pt->next = p->next;    p->next = pt;        return head;}void printLink(link * head){    link * p = head->next; //头结点内容不输入    while(p != NULL){        printf("%d ",p->x);        p = p->next;    }    printf("\n");}void destoryLink(link * head){    link * p = head;    while(p != NULL){        head = p->next;        free(p);        p = head;    }}int main() {    int cnt, del, add;    link * head = (link*)malloc(sizeof(link)); // 带头结点//    head = initLink(head);        printf("此链表各个结点的数据域为：");    printLink(head);        printf("输出要插入的数据个数：");    scanf("%d",&cnt);    printf("输出要插入的数据x: ");    for(int i = 0;i < cnt;i++){        scanf("%d", &add);        insertLink(head, add);    }    printf("以后链表各个结点的数据域为：");    printLink(head);            printf("输出要删除的数据x: ");    scanf("%d", &del);    deleteLink(head, del);        printf("删除后链表各个结点的数据域为：");    printLink(head);            destoryLink(head);    return 0;    }