7 线性表-栈-顺序存储的拓展-迎面增长的存储方式

描述：
设有两个栈，S1和S2，都采用顺序栈的存储方式。
两个栈共享一个存储区：【0，……maxsize-1】
目的：可以尽量利用空间，减少溢出的可能，采用栈顶相向、迎面增长的存储方式

PS：要注意判断栈满栈空的检查

#include<stdio.h>
#include<stdlib.h>
#include<iostream>
using namespace std;
#define maxsize 100

/*栈结构的定义*/
typedef struct
{
    int stackk[maxsize];
    int top[2];//两个栈顶指针top[0]指向stackk左端，top[1]指向stackk右端
    int length[2];
} stk;
/*入栈*/
/*i表示两个不同的栈，0表示左边的栈，1表示右边的栈
左边的栈每入栈一个元素指针向右移动，右边的栈每入栈一个元素指针向左移动
入栈操作前要判断栈是否为满
*/
void initStackk(stk *S)
{
    S->length[0]=0;
    S->length[1]=0;
    S->top[0]=-1;
    S->top[1]=maxsize;
}
int Push(int i,int x,stk *S)
{
    if(i!=0&&i!=1)
    {
        cout<<"wrong stack number"<<endl;
        return 0;
    }
    else if(S->top[0]==(S->top[1]-1))
    {
        cout<<"the stack is filled with data";
        return 0;
    }
    if(i==0)
    {
        S->stackk[++S->top[0]]=x;
        S->length[i]++;
    }
    else
    {
        S->stackk[--S->top[1]]=x;
        S->length[i]++;
    }
    cout<<"Successful."<<endl;
    return 1;
}
int Pop(int i,int &x,stk *S)
{
    if(i!=0&&i!=1)
    {
        cout<<"wrong stack number"<<endl;
        return 0;
    }
    if(S->top[i]==-1||S->top[i]==maxsize)
    {
        cout<<"Stack"<<i<<" is null.";
        return 0;
    }
    if(i==0)
    {
        x=S->stackk[S->top[i]--];
        S->length[i]--;
    }
    else
    {
        x=S->stackk[S->top[i]++];
        S->length[i]--;
    }
    cout<<"Successful."<<endl;
    return 1;
}
void showtheStack(stk *S)
{
    cout<<"Stack0 : ";
    for(int i=0; i<S->length[0]; i++)
        cout<<S->stackk[i]<<" ";
    cout<<endl;
    cout<<"Stack1 : ";
    for(int i=maxsize-1,j=0; j<S->length[1]; j++,i--)
    {
        cout<<S->stackk[i]<<" ";
    }
    cout<<endl;
}
int main()
{
    stk *S=(stk*)malloc(sizeof(stk));
    initStackk(S);
    cout<<"test function 'Push' by input 5 data."<<endl;
    int w=5;
    while(w--)
    {
        cout<<"input a data and which stack that you want to save";
        int a,b;
        cin>>a>>b;

        if(!Push(b,a,S))
        {
            w++;
        }
    }
    showtheStack(S);
    cout<<"test function 'Pop' by input the stack number."<<endl;
    w=3;
    while(w--)
    {
        int out=-1;
        cout<<"input a stack number (0/1):";
        int in;
        cin>>in;
        if(!Pop(in,out,S))
        {
            w++;
        }
        if(out>0)
        {
            cout<<"you Pop the data "<<out<<" successful from stack"<<in<<"."<<endl;
        }
    }
    showtheStack(S);
    return 0;
}