#include<stdio.h>
#include<stdlib.h>
typedef int DataType; 
typedef struct node{
	DataType data;
	struct node* portion;
}Node;
Node* init() //初始化单链表 
{
	Node* A = (Node*)malloc(sizeof(Node));
	A->data = 0;
	A->portion = NULL;
	return A;
}
void headwrite(Node* A,DataType data) //头插法 
{
	Node* P = (Node*)malloc(sizeof(Node));
	P->data = data;
	P->portion = A->portion;
	A->portion = P;
}
Node* findtrail(Node* A) //寻找尾节点，只有找到尾节点，才能尾插法 
{
	Node* P = (Node*)malloc(sizeof(Node));
	P = A;
	while(P->portion != NULL)
	{
		P= P->portion;
	}
	return  P;
}
void trailwrite(Node* A,DataType data)  //尾插法，只有找到尾节点，才能尾插法 
{
	Node* P = (Node*)malloc(sizeof(Node));
	Node* Q = (Node*)malloc(sizeof(Node));
	P = findtrail(A);
	Q->data = data;
	P->portion = Q;
	Q->portion = NULL;	
}
int deletedata(Node* A,int portion) //删除节点 
{
	int i = 0;
	Node* P = (Node*)malloc(sizeof(Node));
	Node* Q = (Node*)malloc(sizeof(Node));
	P = A;
	while(i < portion - 1)
	{
		P = P->portion;
		i ++;
		if(P == NULL)
		{
			printf("删除节点错误，请重新选择位置");
			return 0;
		}
		  
	}
	Q = P->portion;
	P->portion = Q->portion;
	free(Q);
 } 
int insertdata(Node* A,int portion,DataType data) //指定位置插入数据 
{
	int i = 0;
	Node* P = (Node*)malloc(sizeof(Node));
	Node* Q = (Node*)malloc(sizeof(Node));
	P = A;
	while(i < portion - 1)
	{
		P = P->portion;
		i ++;
		if(P == NULL)
			return 0;
	}
	if(P->portion == NULL)
	{
		printf("删除的位置错误\n");
		return 0;
	}
	 
	Q->data = data;
	Q->portion = P->portion;
	P->portion = Q;
}
void read(Node* A) //输出链表数据 
{
	Node* P = (Node*)malloc(sizeof(Node));
	P = A->portion;
	while(P != NULL)
	{
		printf("%d ",P->data);
		P = P->portion;
	}
	printf("\n");
}
int main()
{
	int i = 0;
	Node* H = init();
	for(i = 0;i < 10;i ++)
	{
		headwrite(H,i + 10); //头插法插入数据 
	}
	read(H);//输出数据 
	trailwrite(H,80); //尾插法插入数据 
	trailwrite(H,90);//尾插法插入数据 
	read(H);//输出数据 
	deletedata(H,3);//指定位置删除数据 
	read(H);//输出数据 
	insertdata(H,4,100);//指定位置插入数据 
	read(H);//输出数据 
	free(H); //释放数据 
	return 0;
 }