顺序栈---基本方法

#include<stdio.h> 

#include<stdlib.h>

#include<malloc.h>

#define maxsize 50

using namespace std;

typedef int elemtype;

typedef struct {

elemtype data[maxsize];

int front,rear;

}sqqueue;

void Initqueue(sqqueue*&q)

{

q=(sqqueue*)malloc(sizeof(sqqueue));

q->front=q->rear=-1;

}

bool enqueue(sqqueue*&q,elemtype &e)

{

if(q->rear==maxsize-1)

return false;

q->rear++;

q->data[q->rear]=e;

return true;

 } 

 bool dequeue(sqqueue*&q,elemtype &e)

 {

  if(q->rear==q->front)

  return false;

  q->front++;

  e=q->data[q->front];

  return true;

  }

void destroyqueue(sqqueue *&q)

{

free(q);

}

int main()

{

sqqueue *p;

Initqueue(p);

int n;

scanf("%d",&n);

for(int i=0;i<n;i++)

{    int a,e,m,h;

scanf("%d",&a);

if(a==1)

{   scanf("%d",&h);

enqueue(p,h);

}

else if(a==2)

{

if(dequeue(p,m))

{

printf("%d\n",m);

}

else

{

  printf("no");

  exit(0);

      }

}

else if(a==3)

{

int c=p->rear-p->front;

printf("%d\n",c);

}

}

destroyqueue(p);

return 0;

}