c语言编写的带头节点的增删改查

// 带头节点的链表的增删改差
#include 
#include
#include 
typedef  struct LNode{
	int data;
	struct LNode *next;
}LNode;


LNode * List_HeadInsert(int n){//头插法建立链表
	LNode *head,*s;
	int a;
	head = (LNode *)malloc(sizeof(LNode));
	if(head == NULL){
		printf("建立失败n");
		return 0;
		
	}
	head->next = NULL;
	for(int i=0;inext = head->next;
		s->data=a;
		head->next = s;
	}
	
	return head;
	
}


LNode * create(int n){//尾插法创建一个有n个节点且带头节点的单链表
	LNode *head,*p,*s;
	int a;
	head = (LNode *)malloc(sizeof(LNode));
	head->next = NULL;
	p = head;
	if (head == NULL) {
		printf("建立失败n");
		return 0;
	}
	printf("请输入%d个数字n",n);
	for(int i=0;idata = a;
		s->next = NULL;
		p->next = s;
		p = p->next;
	}
	
	return head;
	
}





LNode * InsertList(LNode *L,int n,int elem)//在第n个位置插入元素elem
{LNode *p,*s;
	p=L;
	for(int i=1;inext;
	}
	
	s=(LNode *)malloc(sizeof(LNode));
	if(s == NULL){
		printf("节点建立失败");
		return 0;
		
	}
	s->data = elem;
	s->next = p->next;
	p->next = s;
	printf("在第%d位置插入数据%d成功n",n,elem);
	return L;
}


LNode * DeletList(LNode *L,int n){//删掉第i个数据
	LNode *p,*s;
	p=L;
	for (int i=1; inext;
	}
	s = p->next;
	p->next = p->next->next;
	free(s);
	printf("删除第%d位的数据成功n",n);
	return L;
	
}

LNode * ChangeList(LNode *L,int n,int elem){ //将第n位的数据更改为elem
	LNode *p;
		p=L;
		for(int i=1;inext;
		}
		p->next->data = elem;
		printf("将第%d位的节点的数据更改为%d成功n",n,elem);
		return L;
	
}


LNode * SearchList1(LNode *L,int n){//按位查找
	LNode *p;
		p=L;
		for(int i=1;inext;
		}
		printf("第%d位的数据为%dn",n,p->next->data);
	return L;

}

void SearchList2(LNode *L,int elem){//按值查找
	LNode *p;
	p=L;
	int i = 0;
	while(p->next){
i++;
		p = p->next;

	if (p->data == elem) {
						break;
	}
}
	printf("数值%d在此链表中的位置为：%dn",elem,i);

	//return i;

}



void display(LNode *L) {//遍历输出链表
	LNode *temp = L;  //创建一个临时结点用来遍历
	temp = L;
	//只要temp->next不指向NULL就输出
	printf("此链表的存储数据为n");
	while (temp->next) {
		temp = temp->next;
		printf("%d", temp->data);
	}
	printf("n");
}

	

int main(){
	LNode *L,*G;
	int a,b,c;
	printf("请输入头插法初始链表的个数：");
	scanf("%d",&a);

	G = List_HeadInsert(a);
	display(G);
	
	printf("请输入尾插法初始链表的个数：");
	scanf("%d",&b);

	L = create(b);
	display(L);
	
	L = InsertList(L, 2, 4);
	display(L);
	
	
	L = DeletList(L, 3);
	display(L);
	
	L = ChangeList(L, 4, 8);
	display(L);
	
	L = SearchList1(L, 4);
	
	SearchList2(L, 8);
}