#include<stdio.h>
#include<stdlib.h>
typedef int ElemType;
typedef struct node {
	ElemType data;
	struct node *next;
}Node;
typedef Node* PtrToNode;
typedef PtrToNode List;
typedef PtrToNode Position;

//判斷是否是空連結串列
int IsEmpty(List L) {
	return L->next == NULL;
}

//判斷是否是末尾
int IsLast(Position P, List L) {
	return P->next == NULL;
}

//尋找
Position Find(ElemType X, List L) {
	Position P;
	P = L->next;
	while (P != NULL && P->data != X) {
		P = P->next;
	}
	return P;
}

Position FindPrevious(ElemType X, List L) {
	Position P;
	P = L;
	while (P->next != NULL && P->next->data != X) {
		P = P->next;
	}
	return P;
}

void Delete(ElemType X, List L) {
	Position P, Tmp;
	P = FindPrevious(X, L);
	if (!IsLast(P,L)) {
		Tmp = P->next;
		P->next = Tmp;
		free(Tmp);
	}
}

//根據位置來插入元素  
void InSert(ElemType X, List L, Position P) {
	Position TmpCell;
	TmpCell = (List)malloc(sizeof(Node));
	if (TmpCell == NULL) {
		printf("Out of space!!!");
	}
	TmpCell->data = X;
	TmpCell->next = P->next;
	P->next = TmpCell;
}


//輸出連結串列  
void PrintList(List L) {
	Position P;
	P = L;

	while (P != NULL) {
		printf("%d ", P->data);
		P = P->next;
	}
	printf("\n");
}

//建立連結串列  
List CreatedList() {
	Position head, p1, p2;
	int n;
	p2 = p1 = (Node*)malloc(sizeof(Node));
	if (p1 == NULL) {
		printf("Can not create p1!!!");
		return NULL;
	}
	else {
		head = NULL;
		n = 0;
		printf("請輸入資料：");
		scanf_s("%d", &(p1->data));
		while (p1->data != 0) {
			n++;
			if (n == 1) {
				head = p1;
				p2->next = NULL;
			}
			else {
				p2->next = p1;
			}
			p2 = p1;

			p1 = (struct node*)malloc(sizeof(struct node));
			printf("請輸入資料：");
			scanf_s("%d", &(p1->data));
		}
		p2->next = NULL;
		free(p1);
		p1 = NULL;
		return head;
	}
}

//刪除連結串列  
void DeLeteList(List L) {
	Position P, Tmp;

	P = L->next;
	L->next = NULL;
	while (P != NULL) {
		Tmp = P->next;
		free(P);
		P = Tmp;
	}
}

//生成空連結串列  
List MakeEmpty(List L) {
	L = (struct node*)malloc(sizeof(struct node));
	L->data = 0;
	L->next = NULL;
	return L;
}

//返回頭結點  
Position Header(List L) {
	return L;
}

//返回第一個資料節點的位置  
Position First(List L) {
	if (L->next != NULL)
		return L->next;
}

//獲得位置P後繼節點位置  
Position Advance(Position P) {
	if (P != NULL)
		return P->next;
}

//返回P位置的資料  
ElemType Retrieve(Position P) {
	if (P != NULL)
		return P->data;
}