c语言数据结构——单链表操作(全)

#include 
#include 

#define ERROR 0
#define OK 1

typedef int ElemType;
typedef int Status;

typedef struct LNode{
	ElemType data;
	struct LNode *next;
}LNode, *LinkList;

// 头插法建立单链表
LinkList List_Head(LinkList &L){
	LNode *s; int x;
	L = (LinkList)malloc(sizeof(LNode));
	L->next = NULL;
	scanf("%d", &x);
	while(x!=-1){
		s = (LinkList)malloc(sizeof(LNode));
		s->data = x;
		s->next = L->next;
		L->next = s;
		scanf("%d", &x);
	}
	return L;
}

// 尾插法建立单链表
LinkList List_TailInsert(LinkList &L){
	int x;
	L = (LinkList)malloc(sizeof(LNode));
	LNode *s, *r = L;
	scanf("%d", &x);
	while(x != -1){
		s = (LinkList)malloc(sizeof(LNode));
		s->data = x;
		r->next = s;
		r = s;
		scanf("%d", &x);
	}
	r->next = NULL;
	return L;
}

LNode *ElemGet(LinkList L, int i){
	if(i < 1) return ERROR;
	int j = 1;
	LNode *p = L->next;
	if(!p || j > i) return NULL;
	while(p && j < i){
		p = p->next;
		j++;
	}
	return p;
}

// 在i位置前插入节点(时间复杂度最坏为O(n))
LinkList List_Insert(LinkList &L, int i, ElemType e){
	LinkList p = ElemGet(L, i - 1);
	LinkList s = (LinkList)malloc(sizeof(LNode));
	s->data = e;
	s->next = p->next;
	p->next = s;
	return L;
}

// 在i位置前插入节点(时间复杂度为O(1))
LinkList List_TailInsert(LinkList &L, int i, ElemType e){
	LinkList p = ElemGet(L, i);
	LinkList s = (LinkList)malloc(sizeof(LNode));
	s->next = p->next;
	s->data = e;
	int temp = p->data;
	p->data = s->data;
	s->data = temp;
	p->next = s;
	return L;
}

// 删除前驱节点(时间复杂度O(n))
LinkList List_Del(LinkList &L, int i){
	LinkList p = ElemGet(L, i - 1);
	LinkList q = (LinkList)malloc(sizeof(LNode));
	q = p->next;
	p->next = q->next;
	free(q);
	return L;
}

// 删除前驱节点(时间复杂度O(1))
LinkList List_TailDel(LinkList &L, int i){
	LinkList p = ElemGet(L, i);
	LinkList q = (LinkList)malloc(sizeof(LNode));
	q = p->next;
	p->data = p->next->data;
	p->next = q->next;
	free(q);
	return L;
}

// 输出所有元素
Status GetElem(LinkList L){
	LNode *p;
	p = L->next;
	while(p != NULL){
		printf("%d ", p->data);
		p = p->next;
	}
	return OK;
}

// 查询表中元素是否存在某一数值
Status LocateElem(LinkList L, int i, ElemType &e){
	if(i < 1) return ERROR;
	LinkList p = L->next;
	int j = 1;
	while(p != NULL && j < i){
		p = p->next;
		j++;
	}
	if(!p || j > i) return ERROR;
	e = p->data;
	printf("%d", e);
	return OK;
}

// 求链表的长度
Status ListLength(LinkList L){
	LinkList p = L->next; 
	int j = 0;
	while(p != NULL){
		j++;
		p = p->next;
	}
	return j;
}

int main(){
	LinkList L; 
	/*List_Head(L);*/
	List_TailInsert(L);
	printf("\n");
	GetElem(L);
	printf("\n");
	int len = ListLength(L);
	printf("链表长度为：%d", len);
	printf("\n");
	int e;
	LocateElem(L, 1, e);
	printf("\n");
	int n = 15;
	List_Insert(L, 2, n);
	GetElem(L);
	printf("\n");
	int c = 25;
	List_TailInsert(L, 2, c);
	GetElem(L);
	printf("\n");
	List_Del(L, 4);
	GetElem(L);
	printf("\n");
	List_TailDel(L, 2);
	GetElem(L);
	printf("\n");
	return 0;
}