数据结构:栈
1.定义
一种可以实现“先进后出”的存储结构
栈类似于箱子,往箱子里面放书,先放进去的最后才能拿出来
2.分类
静态栈
动态栈
3.算法
出栈
入栈
4.应用
函数调用
中断
表达式求值
内存分配
缓冲处理
迷宫
5.代码实现
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
//实现栈的功能,先进后出
typedef struct Node
{
int data;
struct Node * pNext;
}NODE, *PNODE;
typedef struct Stack
{
PNODE pTop;
PNODE pBottom;
}STACK, *PSTACK; //STACK 等价于struck Stack*
void Init(PSTACK);
void push(PSTACK, int);
void traverse(PSTACK);
bool pop(PSTACK, int * );
bool empty(PSTACK);
int main()
{
int val;
STACK S; //STACK 等价于struct Stack
Init(&S);
push(&S, 1);
push(&S, 2);
push(&S, 3);
push(&S, 4);
push(&S, 5);
push(&S, 6);
traverse(&S); //遍历输出
if (pop(&S, &val))
{
printf("出栈成功!出栈的元素是%d\n",val);
}
else
{
printf("出栈失败!\n");
}
clear(&S);
traverse(&S);
return 0;
}
void Init(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;
}
}
void push(PSTACK pS, int val)
{
PNODE pNew = (PNODE)malloc(sizeof(NODE));
pNew->data = val;
pNew->pNext = pS->pTop;
pS->pTop = pNew;
return;
}
void traverse(PSTACK pS)
{
if (empty(pS))
{
printf("栈为空,无法遍历");
}
else
{
PNODE p = pS->pTop;
while(p != pS->pBottom)
{
printf("%d ",p->data);
p = p->pNext;
}
}
printf("\n");
// pBottom一直是垃圾值
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,如果出栈失败,则返回false
bool pop(PSTACK pS, int * pVal)
{
if (empty(pS)) //pS本身存放的就是S的地址,if(empt返回true则执行return false)
{
return false;
}
else
{
PNODE r = pS->pTop;
*pVal = r->data;
pS->pTop = pS->pTop->pNext;
free(r);
r = NULL;
return true;
}
}
//clear清空
void clear(PSTACK pS)
{
if (empty(pS))
{
return;
}
else
{
PNODE ClearNode = pS->pTop;
PNODE TempNode = pS->pTop;
// while(ClearNode != pS->pBottom)
// {
// TempNode = ClearNode->pNext;
// free(ClearNode);
// ClearNode = TempNode;
// }
while(ClearNode != NULL) //更容易被理解
{
TempNode = ClearNode;
ClearNode = ClearNode->pNext;
free(TempNode);
}
Init(pS);
}
}
posted on 2019-05-24 13:12 zhaoy_shine 阅读(155) 评论(0) 编辑 收藏 举报