C语言——栈（Stack）

源码：

方式一：

头文件：

#ifndef _STACK_H
#define _STACK_H

struct node;
typedef struct node* stack;

/* 判断栈是否为空 */
int isEmpty(stack s);
/* create stack */
stack createStack(void);
/* release stack */
void releaseStack(stack s);
/* 入栈 */
void push(void *data,stack s);
/* 取栈顶元素 */
void* top(stack s);
/* 出栈 */
void pop(stack s);

#endif

struct node{
	void* data;
	struct node* next;
};

#include 
#include 
#include "stack.h"

int isEmpty(stack s)
{
	return s->next == NULL;
}

stack createStack(void)
{
	stack s;
	s = malloc(sizeof(struct node));
	if (s == NULL){
		puts("create error");
		return 0;
	}
	else{
		s->next = NULL;
		s->data = NULL;
		return s;
	}
}

void releaseStack(stack s)
{
	struct node* element;
	element = s;
	while (element){
		s = s->next;
		free(element);
		element = s;
	}
}

void push(void *data, stack s)
{
	struct node* element;
	element = malloc(sizeof(struct node));
	if (element == NULL)
		puts("create ndoe fail . .");
	else{
		element->data = data;
		element->next = s->next;
		s->next = element;
	}
}

void* top(stack s)
{
	if (isEmpty(s)){
		puts("empty stack in top");
		return NULL;
	}
	return s->next->data; 
}

void pop(stack s)
{
	if (isEmpty(s))
		puts("empty stack in pop");
	else{
		struct node* element;
		element = s->next;
		s->next = element->next;
		free(element);
	}
}

方式二：

#ifndef _STACK2_H
#define _STACK2_H
#define MIN (5)
struct stackArray;
typedef struct stackArray* stack;

/* 判断stack是否为空 */
int isEmpty2(stack s);
/* 判断stack是否已满 */
int isFull2(stack s);
/* 创建stack */
stack createStack2(int maxNum);
/* release stack */
void release2(stack s);
/* 进栈 */
void push2(void* data,stack s);
/* 取栈顶元素 */
void* top2(stack s);
/* 出栈 */
void pop2(stack s);

#endif

struct stackArray{
	int capacity;
	int topOfStack;
	void** array;
};

#include 
#include 
#include "stack2.h"
int main()
{
	stack s;
	s = createStack2(6);
	push2("hello", s);
	push2("word", s);
	push2("...", s);
	push2("hello", s);
	push2("stack", s);
	push2("...", s);
	push2("hello word", s);
	push2("hello word", s);
	printf("%s\n", top2(s));
	pop2(s);
	printf("%s\n", top2(s));
	pop2(s);
	printf("%s\n", top2(s));
	release2(s);
	return 0;
}

int isEmpty2(stack s)
{
	return s->topOfStack == -1;
}

int isFull2(stack s)
{
	return s->topOfStack == s->capacity - 1;
}

stack createStack2(int maxNum)
{
	if (maxNum < MIN){
		puts("stack大小必须大于5");
		return -1;
	}
	stack s;
	s = malloc(sizeof(struct stackArray));
	if (s == NULL){
		puts("create stack error");
		return -1;
	}
	s->array = malloc(sizeof(void*)*maxNum);
	if (s->array == NULL){
		puts("创建stack失败");
		return -1;
	}
	s->capacity = maxNum;
	s->topOfStack = -1;
	return s;
}

void release2(stack s)
{
	if (s != NULL){
		free(s->array);
		free(s);
	}
}

void push2(void* data, stack s)
{
	if (isFull2(s))
		puts("full of stack");
	else
		s->array[++s->topOfStack]=data;
}

void* top2(stack s)
{
	if (!isEmpty(s))
		return s->array[s->topOfStack];
	puts("empty stack");
	return NULL;
}

void pop2(stack s)
{
	if (isEmpty(s))
		puts("empty stack");
	else
		s->topOfStack--;
}