C++-set类

/*
 * @Author: 阡陌
 * @Date: 2021-01-02 15:21:43
 * @LastEditors: 阡陌
 * @LastEditTime: 2021-01-02 19:50:01
 * @FilePath: \c++\exercise.cpp
 */
#include <iostream>
#include <stdlib.h>
using namespace std;
class Set
{
private:
    int n;
    int *pS; //集合元素
public:
    Set()
    {
        n = 0;
        pS = NULL;
    }
    Set(Set const &s)
    {
        n = s.n;
        if (n != 0)
        {
            pS = new int[n + 1];
            for (int i = 1; i <= n; i++) //集合的下标从1开始，集合中不能有重复元素
                pS[i] = s.pS[i];
        }
    }
    ~Set()
    {
        if (pS)
        {
            delete[] pS;
            pS = NULL;
            n = 0;
        }
    }
    void ShowElement() const
    { //输出集合的元素
        int temp = 0;
        for (int i = 1; i < n; i++)
        {
            for (int j = i + 1; j < n; j++)
            {
                if (pS[i] > pS[j])
                {
                    temp = pS[i];
                    pS[i] = pS[j];
                    pS[j] = temp;
                }
            }
        }
        cout << "{";
        for (int i = 1; i < n; i++)
            cout << pS[i] << ",";
        if (IsEmpty())
            cout << "}" << endl;
        else
            cout << pS[n] << "}" << endl;
    }
    bool IsEmpty() const { return n ? false : true; } //判断集合是否为空
    int size() { return n; }
    bool IsElement(int e) const
    {
        for (int i = 1; i <= n; i++)
            if (pS[i] == e)
                return true;
        return false;
    }
    bool operator<=(const Set &s) const; //this <= s判断当前集合是否包于集合s
    bool operator==(const Set &s) const; //判断集合是否相等
    Set &operator+=(int e);              // 向集合中增减元素e
    Set &operator-=(int e);              //删除集合中的元素e

    Set operator|(const Set &s) const; //集合并
    Set operator&(const Set &s) const; //集合交
    Set operator-(const Set &s) const; //集合差
};
bool Set::operator<=(const Set &s) const
{
    bool a = 1;
    for (int i = 1; i < n + 1; i++)
    {
        if (!s.IsElement(pS[i]))
        {
            a = 0;
            break;
        }
    }
    return a;
}
bool Set::operator==(const Set &s) const
{
    bool a = 1;
    if (n != s.n)
    {
        a = 0;
        return a;
    }
    for (int i = 1; i < n + 1; i++)
    {
        if (!s.IsElement(pS[i]))
        {
            a = 0;
            break;
        }
    }
    return a;
}
Set &Set::operator-=(int e)
{
    Set &that = *this;
    for (int i = 0; i < n; i++)
    {
        if (pS[i] == e)
        {
            pS[i] = pS[n - 1];
            n -= 1;
            delete (pS + n - 1);
        }
    }
    return that;
}
Set &Set::operator+=(int e)
{
    Set &that = *this;
    if (!IsElement(e))
    {
        int *pt = new int[n + 2];
        for (int i = 1; i <= n; i++)
            pt[i] = pS[i];
        pt[n + 1] = e;
        pS = pt;
        n++;
    }
    return that;
}
Set Set::operator&(const Set &s) const
{
    Set p;
    for (int i = 1; i < s.n + 1; i++)
    {
        if (IsElement(s.pS[i]))
        {
            p += s.pS[i];
        }
    }
    return p;
}
Set Set::operator|(const Set &s) const
{
    Set p;
    for (int i = 1; i < s.n + 1; i++)
    {
        p += s.pS[i];
    }
    for (int i = 1; i < n + 1; i++)
    {
        p += pS[i];
    }
    return p;
}
Set Set::operator-(const Set &s) const
{
    Set p, t;
    p = *this | s;
    t = *this;
    for (int i = 1; i < p.n + 1; i++)
    {
        t -= p.pS[i];
    }

    return t;
}
int main()
{
    Set p;
    for (int i = 0; i < 50; i += 3)
    {
        p += i;
    }
    Set t;
    for (int i = 0; i < 50; i += 2)
    {
        t += i;
    }
    Set h=t&p;
    h.ShowElement();
    system("pause");
    return 0;
}