文章目录
栈
栈定义
一种可以实现“先进后出” 的存储结构,栈类似于箱子
栈的分类
- 静态栈 (类似于用数组实现)
- 动态栈 (类似于用链表实现)
栈的算法(c语言实现)
#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
typedef enum _bool{
false = 0,true = 1} bool;
typedef struct Node
{
int data;
struct Node * pNext;
}NODE,* PNODE;
typedef struct stack
{
PNODE pTop;
PNODE pBottom;
}STACK,* PSTACK;
void init_stack(PSTACK);
void push_stack(PSTACK,int);
void traverse_stack(PSTACK);
bool pop_stack(PSTACK,int *);
bool empty(PSTACK);
void clear_stack(PSTACK);
//初始化栈,制造出一个空栈
void init_stack(PSTACK pS)
{
pS->pTop = (PNODE)malloc(sizeof(NODE));
if(NULL == pS->pTop)
{
printf("动态内存分配失败\n");
exit(-1);
}
else
{
pS->pBottom = pS->pTop;
pS->pTop->pNext = NULL; //pS->pBottom->pNext = NULL;
}
return ;
}
//压栈
void push_stack(PSTACK pS,int val)
{
PNODE pNew = (PNODE)malloc(sizeof(NODE));
pNew->data = val;
pNew->pNext = pS->pTop; //pS->Top 不能改成pS->pBottom
pS->pTop = pNew;
return ;
}
//遍历
void traverse_stack(PSTACK pS)
{
PNODE p = pS->pTop;
while(p != pS->pBottom)
{
printf("data in stack is %d\n",p->data);
p = p->pNext;
}
printf("\n");
return ;
}
bool empty(PSTACK pS)
{
if(pS->pTop == pS->pBottom)
return true;
else
return false;
}
//把pS所指向的栈出栈一次,并把出栈的元素存入pVal形参所指向的变量中,成功返回真,错误返回假
bool pop_stack(PSTACK pS,int *pVal)
{
if(empty(pS))
{
return false;
}
else
{
PNODE r = pS->pTop;
*pVal = r->data;
pS->pTop = r->pNext;
free(r);
r = NULL;
return true;
}
}
//清空
void clear_stack(PSTACK pS)
{
if(empty(pS))
{
return;
}
else
{
PNODE p = pS->pTop;
PNODE q;
while(p != pS->pBottom)
{
q = p->pNext;
free(p);
p = q;
}
pS->pTop = pS->pBottom;
}
}
int main()
{
STACK S;
int val;
init_stack(&S); //目的是制造出一个空栈
push_stack(&S,1); //压栈
push_stack(&S,2);
push_stack(&S,3);
traverse_stack(&S); //遍历输出
if(pop_stack(&S,&val))
{
printf("pop stack success and the value is %d\n.",val);
}
else
{
printf("pop stack failed\n");
}
traverse_stack(&S); //遍历输出
clear_stack(&S);
printf("clear test \n");
traverse_stack(&S); //遍历输出
return 0;
}
结果输出