C语言编写一个链表

struct node* Creatlist(){//创建链表头
 struct Node *headnode = (struct Node*)malloc(sizeof(struct Node));//创建动态内存链表，指针变量
 headnode->next = NULL;//链表初始化
 return headnode;
}

struct Node* Creatnode(int num){//创建结点，链表,参数数字域
 struct Node* newnode = (struct Node*)malloc(sizeof(struct Node));//创建动态内存链表，指针变量
 newnode->num = num;
 newnode->next = NULL;//链表初始化
 return newnode;
}

void Insetlist(struct Node* list, int num){//头插法
 struct Node* insetnode = Creatnode(num);
 if (list != NULL){
  insetnode->next = list->next;
  list->next = insetnode;
 }
 else{
  printf("节点不存在\n");
 }
}
void Insetlists(struct Node* headnode, int n, int num){//在n节点处插入,参数头节点，在第n个节点处插，插入的数据num
 int i = 1;
 struct Node *t = headnode;
 while (i < n&& t!= NULL){
  t = t->next;
  i++;
 }
 if (t != NULL){
  struct Node* insetnode = Creatnode(num);
  insetnode->next = t->next;
  t->next = insetnode;
 }
 else{
  printf("节点不存在\n");
 }
}

void Modifynode(struct Node* headnode, int n){//修改节点，参数链表，修改的第n个节点
 struct Node* list = headnode;
 int i = 0;
 while (i < n&&list != NULL){
  list = list->next;
  i++;
 }
 if (list != NULL){
  printf("请输入你要修改的值\n");
  int j = 0;
  scanf("%d", &j);
  list->num = j;

 }
 else{
  printf("节点不存在\n");
 }
}

void Deletnode(struct Node* headnode, int n){//删除第n个节点，
 int i = 1;
 struct Node *strat = headnode;
 struct Node *end = headnode->next;

 while (i < n&&end != NULL){
  strat = strat->next;
  end = end->next;
  i++;
 }
 if (end != NULL){
  strat->next = end->next;
  free(end);

 }
 else{
  printf("节点不存在\n");
 }
}

void Printnode(struct Node* headnode){//打印节点
 struct Node* list = headnode;
 while ((list->next) != NULL){
  list = list->next;
  printf("%d\t",  list->num);
 }
 printf("\n");

}

int main(){
 struct Node* list = Creatlist();

 Insetlists(list, 1, 1);
 Printnode(list);
 int i = 0;
 printf("请输入修改哪个节点\n");
 scanf("%d", &i);
 Modifynode(list, i);
 Printnode(list);
 printf("请输入删除哪个节点\n");
 int n = 0;
 scanf("%d", &n);
 Deletnode(list, n);
 Printnode(list);
 system("pause");
 return 0;
}