Design Patterns - Composite

files_folders.cpp

#include <iostream>
#include <string>
#include <vector>
using namespace std;

class Item {
    protected:
        string ten;

    public:
        Item(string ten): ten(ten) {}
        virtual ~Item() {}
        virtual string getKieu() = 0;
        virtual int getDungLuong() = 0;
};

class File: public Item {
    private:
        int dungLuong;

    public:
        File(string ten, int dungLuong): Item(ten), dungLuong(dungLuong) {}
        string getKieu() override { return "File"; }
        int getDungLuong() override { return dungLuong; }
};

class Folder: public Item {
    private:
        vector<Item *> dsCon;

    public:
        Folder(string ten): Item(ten) {}
        string getKieu() override { return "Folder"; }
        void themCon(Item *con) { dsCon.push_back(con); }

        int demFile() {
            int dem = 0;
            for (Item *con: dsCon) {
                if (con->getKieu() == "File") dem += 1;
                else dem += ((Folder *)con)->demFile();
            }
            return dem;
        }

        int getDungLuong() override {
            int tong = 0;
            for (Item *con: dsCon)
                tong += con->getDungLuong();
            return tong;
        }
};

int main() {
    Folder *lapTrinh = new Folder("lap trinh");
    File *taiLieu = new File("tai lieu.pdf", 2000);

    Folder *baiTap = new Folder("bai tap");
    File *bt01 = new File("bt01.cpp", 500);
    File *bt02 = new File("bt02.cpp", 600);

    lapTrinh->themCon(taiLieu);
    lapTrinh->themCon(baiTap);

    baiTap->themCon(bt01);
    baiTap->themCon(bt02);

    cout << lapTrinh->getDungLuong() << endl;
    cout << lapTrinh->demFile() << endl;

    return 0;
}

resistor.cpp

#include <iostream>
#include <string>
#include <vector>
using namespace std;

class DienTro {
    public:
        virtual ~DienTro() {}
        virtual double getR() = 0;
};

class DienTroDon: public DienTro {
    private:
        double r;

    public:
        DienTroDon(double r): r(r) {}
        double getR() override { return r; }
};

class DienTroNoiTiep: public DienTro {
    private:
        vector<DienTro *> dsCon;

    public:
        void themCon(DienTro *con) { dsCon.push_back(con); }
        double getR() override {
            double tong = 0;
            for (DienTro *con: dsCon)
                tong += con->getR();
            return tong;
        }
};

class DienTroSongSong: public DienTro {
    private:
        vector<DienTro *> dsCon;

    public:
        void themCon(DienTro *con) { dsCon.push_back(con); }
        double getR() override {
            double tong = 0;
            for (DienTro *con: dsCon)
                tong += 1 / con->getR();
            return 1 / tong;
        }
};

int main() {
    DienTroDon *r1 = new DienTroDon(1);
    DienTroDon *r2 = new DienTroDon(2);
    DienTroDon *r3 = new DienTroDon(6);
    DienTroDon *r4 = new DienTroDon(4);

    DienTroSongSong *r23 = new DienTroSongSong();
    r23->themCon(r2);
    r23->themCon(r3);

    DienTroNoiTiep *rAB = new DienTroNoiTiep();
    rAB->themCon(r1);
    rAB->themCon(r23);
    rAB->themCon(r4);

    cout << rAB->getR() << endl;
    return 0;
}