===== Struktury =====

<code C++>
#include <iostream>
using namespace std;

struct Item
{
    string name;
    int    r, g, b;
};

void print (Item & t)
{
    cout << t.name << " " << t.r << "," << t.g << "," << t.b << endl;
}

int main()
{
    Item c;
    c.name = "cervena";
    c.r = 255;
    c.g = 0;
    c.b = 0;

    Item m;
    m.name = "modra";
    m.r = 0;
    m.g = 0;
    m.b = 255;

    print (c);
    print (m);

    return 0;
}
</code>


===== Funkce swap s parametry předávanými odkazem =======

<code C++>
#include <iostream>
using namespace std;

void swap0 (int x, int y) // nefunguje
{
    int t = x;
    x = y;
    y = t;
    cout << "(" << x << ", " << y << ")"<< endl;
}

inline void swap (int & x, int & y) 
{
    int t = x;
    x = y;
    y = t;
}

int main()
{
    int a = 1;
    int b = 2;
    cout << a << ", " << b << endl;
    swap (a, b);
    cout << a << ", " << b << endl;

    int p[10];
    swap (p[0], p[1]);

    return 0;
}
</code>

===== Ukazatele =====

<code C++>
#include <iostream>
using namespace std;

struct Item
{
    string name;
    int    r, g, b;
    Item* next;
};

Item* first = nullptr; // prazdny seznam

void print(Item* t)
{
    cout << t->name << " " << t->r << "," << t->g << "," << t->b << endl;
}

int main()
{
    Item* c = new Item;
    c->name = "cervena";
    c->r = 255;
    c->g = 0;
    c->b = 0;

    Item* z = new Item;
    z->name = "zelena";
    z->r = 0;
    z->g = 255;
    z->b = 0;

    Item* m = new Item;
    m->name = "modra";
    m->r = 0;
    m->g = 0;
    m->b = 255;

    // Item * u = z;
    // u->name = "svetle zelena";
    // u->r += 128;
    // u->b += 128;

    first = c;
    c->next = z; // za cervenou bude zelena
    z->next = m;
    m->next = nullptr; // za modrou nebude nic

    // first->next = z;
    // first->next->next = m;
    // first->next->next->next = nullptr;

    // print (first);
    // print (first->next);
    // print (first->next->next);

    Item* u = first;
    while (u != nullptr)
    {
        print(u);
        u = u->next;
    }

    return 0;
}
</code>

===== Vkládání do seznamu =====

<code C++>
#include <iostream>
using namespace std;

struct Item
{
    string name;
    int    r, g, b;
    Item * next;
};

Item * first = nullptr;

void insertFirst (string name0, int r0, int g0, int b0)
{
    Item * t = new Item;
    t->name = name0;
    t->r = r0;
    t->g = g0;
    t->b = b0;
    t->next = first;

    first = t;
}

void insertLast (string name0, int r0, int g0, int b0)
{
    Item * t = new Item;
    t->name = name0;
    t->r = r0;
    t->g = g0;
    t->b = b0;
    t->next = nullptr; // nikdo za mnou nebude

    if (first == nullptr)
    {
       first = t;
    }
    else
    {
        Item * p = first;
        while (p->next != nullptr)
        {
            p = p->next;
        }
        p->next = t; // pripojime za posledni
    }
}

Item * find (string name0)
{
    Item * p = first;
    while (p != nullptr && p->name != name0)
    {
        p = p->next;
    }
    return p;
}

void print ()
{
    Item * t = first;
    while (t != nullptr)
    {
        cout << t->name << " " << t->r << "," << t->g << "," << t->b << endl;
        t = t->next;
    }
}

int main()
{
    insertLast ("cervena", 255, 0, 0);
    insertLast ("zelena", 0, 255, 0);
    insertLast ("modra", 0, 0, 255);

    Item * t = find ("zelena");
    if (t == nullptr) 
        cout << "nenasli" << endl;
    else
        cout << "nasli " << t->name << ", " << t->r << ", " << t->g << ", " << t->b << endl;

    print ();

    return 0;
}
</code>

{{seznam.png}}

  * cervena policka jsou typu //Item *// (ukazatel na strukturu Item)
  * zluta jsou typu //string//
  * modra typu //int//

Nakresleno pomocí https://app.diagrams.net/

===== Vymazávamí ze seznam =====

<code C++>
#include <iostream>
#include <cassert>
using namespace std;

struct Item
{
    string name;
    int    r, g, b;
    Item * next;
};

Item * first = nullptr;

void insertFirst (string name0, int r0, int g0, int b0)
{
    Item* t = new Item;
    t->name = name0;
    t->r = r0;
    t->g = g0;
    t->b = b0;
    t->next = first;

    first = t;
}

void insertLast (string name0, int r0, int g0, int b0)
{
    Item* t = new Item;
    t->name = name0;
    t->r = r0;
    t->g = g0;
    t->b = b0;
    t->next = nullptr; // nikdo za mnou nebude

    if (first == nullptr)
    {
        first = t;
    }
    else
    {
        Item * p = first;
        while (p->next != nullptr)
        {
            p = p->next;
        }
        p->next = t; // pripojime za posledni
    }
}

void insertAfter (Item * target, string name0, int r0, int g0, int b0) // vlozit novy prvek za target
{
    assert (target != nullptr);

    Item* t = new Item;
    t->name = name0;
    t->r = r0;
    t->g = g0;
    t->b = b0;
    t->next = target->next; // za novym prvkem bude naslednik prvku target

    target->next = t; // za target bude novy prvek
}

void remove (Item* target) // odstranit prvek target
{
    assert (target != nullptr);

    if (target == first)
    {
        first = target->next;
    }
    else
    {
        Item* p = first;
        while (p != nullptr && p->next != target)
        {
            p = p->next;
        }
        assert (p != nullptr);

        p->next = target->next;
    }

    delete target;
}


Item* find (string name0)
{
    Item* p = first;
    while (p != nullptr && p->name != name0)
    {
        p = p->next;
    }
    return p;
}

void print ()
{
    Item* t = first;
    while (t != nullptr)
    {
        cout << t->name << " " << t->r << "," << t->g << "," << t->b << endl;
        t = t->next;
    }
}

/*
void light (int & h)
{
    h = h + 128;
    if (h > 255) h = 255;
}
*/

int main()
{
    insertLast ("cervena", 255, 0, 0);
    insertLast ("zelena", 0, 255, 0);
    insertLast ("modra", 0, 0, 255);

    Item* t = find ("zelena");
    if (t == nullptr)
        cout << "nenasli" << endl;
    else
    {
        cout << "nasli " << t->name << ", " << t->r << ", " << t->g << ", " << t->b << endl;
        insertAfter (t, "zluta", 192, 192, 0);
        remove (t);
        /*
        t->name = "svetle " + t->name;
        light (t->r);
        light (t->g);
        light (t->b);
        */
    }

    cout << endl;
    print();

    while (first != nullptr)
    {
        remove (first);
    }

    print();
    return 0;
}
</code>