链栈实现（C语言）

 所谓链栈，就是用链的方式来实现栈，我们之前对链和栈都有过学习，所以实现起来相对简单

为什么要用链来实现栈呢？我们知道链的尾插和尾删都很容易实现，所以我们可以用链来实现栈

栈：先进后出，后进先出

链：有头节点（相对简单）每次入栈就是在链后面进行插入，出栈就是删除最后一个节点

头文件的设计

typedef int ELEM_TYPE;
typedef struct Lstack {
	ELEM_TYPE data;
	struct  Lstack* next;
}Lstack,*PLstack;

void Init_lstack(PLstack pls);
struct Lstack* BuyNode(ELEM_TYPE val);
bool Push(PLstack pls,ELEM_TYPE val);
bool Pop(PLstack pls, ELEM_TYPE* rtval);
bool Top(PLstack pls, ELEM_TYPE* rtval);
int Get_length(PLstack pls);
bool IsEmpty(PLstack pls);
void Clear(PLstack pls);
void Destory(PLstack pls);
void show(PLstack pls);

头文件声明的定义 

#include
#include
#include
#include"LStack.h"
void Init_lstack(PLstack pls) {
	assert(pls!=NULL);
	pls->next = NULL;
}
struct Lstack* BuyNode(ELEM_TYPE val) {
	struct Lstack* pnewnode = (struct Lstack*)malloc(sizeof(struct Lstack));
	assert(pnewnode != NULL);
	if (pnewnode==NULL) {
		return NULL;
	}
	pnewnode->data = val;
	return pnewnode;
}
bool Push(PLstack pls, ELEM_TYPE val) {
	assert(pls != NULL);
	struct Lstack* pnewnode = BuyNode(val);
	if (pnewnode==NULL) {
		return false;
	}
	pnewnode->next = pls->next;
	pls->next = pnewnode;
	return true;
}
bool Pop(PLstack pls, ELEM_TYPE* rtval) {
	assert(pls != NULL);
	if (IsEmpty(pls)) {
		return false;
	}
	struct Lstack* p = pls->next;
	*rtval = p->data;
	pls->next = p->next;
	free(p);
	p = NULL;
	return true;
}
bool Top(PLstack pls, ELEM_TYPE* rtval) {
	assert(pls != NULL);
	if (IsEmpty(pls)) {
		return false;
	}
	*rtval = pls->next->data;
	return true;
}
int Get_length(PLstack pls) {
	int count = 0;
	for (struct Lstack* p = pls->next; p != NULL;p=p->next) {
		count++;
	}
	return count;
}
bool IsEmpty(PLstack pls) {
	return pls->next == NULL;
}
void Clear(PLstack pls) {
	Destory(pls);
}
void Destory(PLstack pls) {
	assert(pls!=NULL);
	while (pls->next!=NULL) {
		struct Lstack* p = pls->next;
		pls->next = p->next;
		free(p);
		p = NULL;
	}
}
void show(PLstack pls) {
	for (struct Lstack* p = pls->next; p != NULL;p=p->next) {
		printf("%5d",p->data);
	}
	printf("n");
}

测试文件

测试用例