3.1.2.2 共享栈（两个）

ShareStack.h

#pragma once
#include<iostream>
using namespace std;

class ShareStack {
public:
    int* v;
    int maxSize;
    int top[2];
    int bottom[2];

    ShareStack(int size = 5) {
        maxSize = size;
        v = new int[maxSize];
        top[0] = bottom[0] = -1;
        top[1] = bottom[1] = maxSize;
    }

    bool IsFull() {
        return top[0] + 1 == top[1];
    }

    void overflowProcess() {
        int* s = new int[maxSize * 2];
        for (int i = 0; i <= top[0]; i++) {
            s[i] = v[i];
        }
        for (int i = maxSize - 1; i >= top[1]; i--) {
            s[i + maxSize] = v[i];
        }
        top[1] += maxSize;
        bottom[1] = 2 * maxSize;
        maxSize *= 2;
        delete[]v;
        v = s;
    }

    void push(int elem, int which) {
        //which表示操作哪个栈
        if (IsFull() == true) {
            overflowProcess();
        }
        if (which == 0) {
            top[0]++;
        }
        else {
            top[1]--;
        }
        v[top[which]] = elem;
    }

    bool pop(int& elem, int which) {
        bool  res;
        if (top[which]==bottom[which]) {
            res = false;
        }
        else {
            elem = v[top[which]];
            if (which == 0) {
                top[0]--;
            }
            else {
                top[1]++;
            }
            res = true;
        }
        return res;
    }


};

main.cpp

#include"ShareStack.h"

int main() {
    ShareStack s;
    int a[] = { 1,3,5,7,9 };
    int b[] = { 2,4,6,8,10 };
    //测试栈溢出处理机制。构造函数默认数组大小为5
    for (int i = 0; i < 5; i++) {
        s.push(a[i], 0);
        s.push(b[i], 1);
    }
    cout << "V:" << endl;
    //原则上不能有下面这种操作，但是为了方便看数组里的元素，不想调试了
    for (int i = 0; i < s.maxSize; i++) {
        cout << s.v[i] << " ";
    }
    cout << endl;
    cout << "top[0]:" << s.top[0] << "  top[1]:" << s.top[1] << endl;
    bool bl;
    int e;
    for (int i = 0; i < 2; i++) {
        while (s.top[i] != s.bottom[i]) {
            bl = s.pop(e, i);
            cout << e << " ";
        }
        cout << endl;
    }

    return 0;
}