// 06 07
//A1

#include <iostream>
using namespace std;

main(){
       int n;
       double p = 1;
       cout << "n eingeben: ";
       cin >> n;
       for (int k=1; k<=n; k++){
           p *= (1 + 1/float(k*k));
       }
       cout << "p_" << n << " = " << p;
       system("Pause");
}


//A2
#include <iostream>

using namespace std;

void reverse (double feld[], int n){
       double hilfe;
       for (int i=0; i<=(n-1)/2; i++){
           hilfe = feld[i];
           feld[i] = feld[n-1-i];
           feld[n-1-i] = hilfe;
       }
}

void init (double feld[], int n){
     for (int i=0; i<=n-1; i++) feld[i] = i;
}

void ausgabe (double feld[], int n){
     for (int i=0; i<=n-1; i++){
         cout << "feld[" << i << "] = " << feld[i] << endl;
     }
}

main(){
       const int laenge = 9;
       double field[laenge];
       init (field, laenge);
       ausgabe (field, laenge);
       cout << "\nreverse wird aufgerufen...\n\n";
       reverse (field, laenge);
       ausgabe (field, laenge);       
       system("Pause");
}

//A3
#include <iostream>
using namespace std;

class tacho{            
            public:
                   tacho(double, double);
                   double get_dist();
                   tacho operator += (tacho);
                   friend double avg_speed (tacho);
            private:
                    double strecke, zeit;
};

tacho::tacho(double s, double z){
            strecke = s;
            zeit = z;
}

double tacho::get_dist(){
       return strecke;
}

tacho tacho::operator +=(tacho t){
      strecke += t.strecke;
      zeit += t.zeit;
}

double avg_speed(tacho fahrt){
       return (fahrt.strecke/fahrt.zeit);
}

int main(){
    tacho trip (0,0);
    trip += tacho (200, 413.5);     // Tram Uni-> Zoo, 2 km, 413.5 sec
    trip += tacho (547.5, 800.3);   // zu Fuss im Zoo, 547.5 m, 800.3 sec
    trip += tacho (2000, 415);      // Tram zu Uni, 2 km, 415 sec
    
    cout << "Gesamtstrecke: " << trip.get_dist() << endl;
    cout << "Durchschnitts-Geschwindigkeit: " << avg_speed(trip) << endl;
    system("Pause");
}


//A4

#include <iostream>
using namespace std;

int f(int z){
    z += 1;
    cout << "UP1: " << z << endl;
    return z*2;
}

int f(int* q){
    (*q) += 2;
    cout << "UP2: " << *q << endl;
    return 13 + (*q)/1000;
}

int f(int r, int s){
    if (s==0) return 0;
    else return r + f(r-1,s-1);
}

int main(){
    int i=9; // <- setzen Sie hier bitte die letzte Ziffer
             //    Ihrer Matrikelnummer ein.
    
    int j=f(i);
    cout << "HP1: " << i << " " << j << endl;
    
    int* p = &i;
    cout << "HP2: " << *p << endl;
    
    j=f(p);
    cout << "HP3: " << i << " " << j << endl;
    
    cout << "HP4: " << f(6,3) << endl;
    
    system("Pause");
}

// Eingesetzte Ziffer: ziffer
UP1: ziffer+1
HP1: ziffer (ziffer+1)*2
HP2: ziffer
UP2: ziffer+2
HP3: ziffer+2 13		// immer 13, da bei Cast zu int die Nachkommastellen abgetrennt werden
HP4: 15				// 6+5+4=15


// Bsp.: ziffer=9
UP1: 10
HP1: 9 20
HP2: 9
UP2: 11
HP3: 11 13
HP4: 15

//A5
#include <iostream>
using namespace std;

main(){
       int n=0, feld[9];
       long zahl, temp, ziffer;
       string schoen = "eine";
       cout << "Zahl eingeben: ";
       cin >> zahl;
       temp = zahl;
       for (int k=0; k<=9; k++) feld[k] = 0;
       while (temp >= 1){
             ziffer = temp % 10;
             feld[ziffer] += 1;
             temp /= 10;
             n++;
       }
       for (int k=0; k<=9; k++){ 
           cout << k << ": " << feld[k] << " mal\n";
           if (k <= n && k != 0 && feld[k] != 1)  schoen = "keine";
           if ((k > n || k == 0) && feld[k] != 0) schoen = "keine";
       }
       cout << zahl << " ist " << schoen << " ziffern-schoene Zahl.\n";
       system("Pause");
}