c语言实现的栈---链表+数组

1.数组实现的栈

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define MAXSIZE 5
/**
*数组实现的栈，缺点，容量固定
**/
typedef struct{
	int data[MAXSIZE];
	int index;
}Stack;
Stack s;
/**
*入栈，成功返回1，否则0
**/
int push(int e){
	int rt = 0;
	if(s.index < MAXSIZE-1){
		s.data[++s.index] = e;
	}else{
		rt = -1;
	}
	return rt;	
}
/**
*初始化栈
*/
int clear(void){
	s.index = -1;
	return 0;
}
/**
*判断栈是否为空
**/
int isempty(void){
	return (s.index == -1)?1:0;
}

/**
*出栈，弹出栈顶元素
**/
int pop(void){
	int t=0;
	if(s.index != -1){
		t=s.data[s.index--];
	}
	return t;
}
/**
*栈内元素打印
*/
int displaystack(void){
	int p=s.index;
	while(s.index!=-1){
		printf("currentdata:%d\n",s.data[s.index--]);
	}
	s.index = p;
	return 0;
}
int main(void){
	clear();
	puts("after push:");
	push(1);
	push(2);
	push(3);
	push(4);
	push(5);
	push(6);
	printf("s.index=%d:\n",s.index);
	displaystack();
	puts("\nafter pop");
	pop();
	displaystack();
	return 0;
}

　　2.链表实现

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

/**
*链表实现的栈
**/
typedef struct linklist{
	int data;
	struct linklist *next;
	struct linklist *pre;
}Link;
typedef struct{
	int index;//栈顶
	int empty;//链表是否为空标志
	Link *head;
}StackLink;
StackLink s;
/**
*入栈
**/
int push(int e){
	Link *element,*end;
	if(s.index==0){
		end = (Link *)malloc(sizeof(Link));
		s.empty = -1;
	}else{
		end = s.head;
	}
	element = (Link *)malloc(sizeof(Link));
	element->data = e;
	element->pre = end;
	element->next = NULL;
	end->next = element;
	end = element;
	s.index ++;
	s.head = end;
	return 0;	
}
/**
*标志位设为空
**/
int clear(){
	s.empty = 0;
	return 0;
}
/**
*判断栈是否为空
**/
int isempty(void){
	return (s.empty==0)?1:0;
}

/**
*出栈，弹出栈顶元素
**/
int pop(void){
	int t=0;
	if(s.index != 0&&s.empty == -1){
		s.index --;
		Link *temp,*p;
		t=s.head->data;
		temp=s.head;
		p = temp->pre;
		free(s.head);
		s.head = p;
	}else{
		s.empty = 0;
	}
	return t;
}
/**
*栈内元素打印
*/
int displaystack(void){
	Link *t = s.head;
	while(s.head->pre!=NULL){
		printf("currentdata:%d\n",s.head->data);
		s.head=s.head->pre;
	}
	s.head = t;
	return 0;
}
int main(void){
	clear();
	puts("after push:");
	for(int i=0;i<100;i++)
		push(i);
	printf("s.index=%d:\n",s.index);
	displaystack();
	puts("\nafter pop");
	pop();
	pop();
	displaystack();
	return 0;
}