链栈

链栈的实现，与君共勉.

#include "stdio.h"

#include "stdlib.h"

#include "io.h"

#include "math.h"

#include "time.h"

#define OK 1

#define ERROR 0

#define TRUE 1

#define FALSE 0

#define MAXSIZE 20 /* 存储空间初始分配量 */

typedef int Status;

typedef int SElemType; /* SElemType类型根据实际情况而定，这里假设为int */

/* 链栈结构 */

typedef struct StackNode

{

SElemType data;

struct StackNode *next;

}StackNode,*LinkStackPtr;

typedef struct

{

LinkStackPtr top;

int count;

}LinkStack;

Status visit(SElemType c)

{

printf("%d ",c);

return OK;

}

/* 构造一个空栈S */

Status InitStack(LinkStack *S)

{

S->top = (LinkStackPtr)malloc(sizeof(StackNode));

if(!S->top)

return ERROR;

S->top=NULL;

S->count=0;

return OK;

}

/* 把S置为空栈 */

S tatus ClearStack(LinkStack *S)

{

LinkStackPtr p,q;

p=S->top;

while(p)

{

q=p;

p=p->next;

free(q);

}

S->count=0;

return OK;

}

/* 若栈S为空栈，则返回TRUE，否则返回FALSE */

Status StackEmpty(LinkStack S)

{

if (S.count==0)

return TRUE;

else

return FALSE;

}

/* 返回S的元素个数，即栈的长度 */

int StackLength(LinkStack S)

{

return S.count;

}

/* 若栈不空，则用e返回S的栈顶元素，并返回OK；否则返回ERROR */

Status GetTop(LinkStack S,SElemType *e)

{

if (S.top==NULL)

return ERROR;

else

*e=S.top->data;

return OK;

}

/* 插入元素e为新的栈顶元素 */

Status Push(LinkStack *S,SElemType e)

{

LinkStackPtr s=(LinkStackPtr)malloc(sizeof(StackNode));

s->data=e;

s->next=S->top; /* 把当前的栈顶元素赋值给新结点的直接后继，见图中① */

S->top=s; /* 将新的结点s赋值给栈顶指针，见图中② */

S->count++;

return OK;

}

/* 若栈不空，则删除S的栈顶元素，用e返回其值，并返回OK；否则返回ERROR */

Status Pop(LinkStack *S,SElemType *e)

{

LinkStackPtr p;

if(StackEmpty(*S))

return ERROR;

*e=S->top->data;

p=S->top; /* 将栈顶结点赋值给p，见图中③ */

S->top=S->top->next; /* 使得栈顶指针下移一位，指向后一结点，见图中④ */

free(p); /* 释放结点p */

S->count--;

return OK;

}

Status StackTraverse(LinkStack S)

{

LinkStackPtr p;

p=S.top;

while(p)

{

visit(p->data);

p=p->next;

}

printf("\n");

return OK;

}

int main()

{

int j;

LinkStack s;

int e;

if(InitStack(&s)==OK)

for(j=1;j<=10;j++)

Push(&s,j);

printf("栈中元素依次为：");

StackTraverse(s);

Pop(&s,&e);

printf("弹出的栈顶元素 e=%d\n",e);

printf("栈空否：%d(1:空 0:否)\n",StackEmpty(s));

GetTop(s,&e);

printf("栈顶元素 e=%d 栈的长度为%d\n",e,StackLength(s));

ClearStack(&s);

printf("清空栈后，栈空否：%d(1:空 0:否)\n",StackEmpty(s));

return 0;

}