数据结构--栈与队列

专题--栈与队列

　　栈：先入后出。

　　队列：先入先出。

#include <iostream>
#include <cstdlib>

using namespace std;

const int MAXSIZE=100;
//顺序存储
struct Stack
{
    int data[MAXSIZE];
    int top;
};
//两栈共享空间结构
struct DStack
{
    int data[MAXSIZE];
    int top1;
    int top2;
};

//链式存储(不需要头结点)
struct StackNode
{
    int data;        //数据域
    StackNode *next; //指针域
};
typedef StackNode *LinkStackPtr;
struct LinkStack
{
    LinkStackPtr top; //头指针
    int count;        //存储元素个数，用来判断链栈是否为空
};
//入栈
bool Push(LinkStack *S,int e)
{
    StackNode *s=new StackNode;
    s->data=e;
    s->next=S->top;

    S->top=s;
    ++S->count;
    return true;

}
//出栈
bool Pop(LinkStack *S,int *e)
{
    if(S->count==0)
        return false;

    *e=S->top->data;

    StackNode *p=S->top;
    S->top=S->top->next;
    delete p;

    --S->count;
    return true;
}
/*****************/
//队列(先进先出)，有头结点
struct QNode
{
    int data;
    QNode *next;
};
typedef QNode *QueuePtr;
struct LinkQueue
{
    QueuePtr front,rear; //头指针和尾指针
};
//入队列
bool EnQueue(LinkQueue *Q,int e)
{
    QNode *s=new QNode;
    if(!s)
        exit(-1);
    s->data=e;
    s->next=nullptr;

    Q->rear->next=s;
    Q->rear=s;
}
//出队列
bool DeQueue(LinkQueue *Q,int *e)
{
    if(Q->front==Q->rear)
        return false;

    QNode *p;
    p=Q->front->next;
    *e=p->data;
    Q->front->next=p->next;

    if(Q->rear==p)          //注意：若队头是队尾，则删除后将rear指向头结点
        Q->rear=Q->front;
    delete p;

    return true;
}