С++ ЕНФ / LABA 5 / MENUV3

# include <iomanip.h>
# include <iostream.h>
# include <stdlib.h>
# include <conio.h>
float zadacha (float &x1, float &y1, float &z1, float &x2, float &y2, float &z2,float &p)
//Zadat' koordinatu vektorov
 {float a,b,c,d,e,f;
  cout<<"vv. koordinati 1 vegtora \n";
  cout<<setw(5)<<"vvedite x "<<endl;
   cin>>a;x1=a;
  cout<<setw(5)<<"vvedite y "<<endl;
   cin>>b;y1=b;
  cout<<setw(5)<<"vvedite z "<<endl;
   cin>>c;z1=c;
  cout<<setw(5)<<"vvedite x"<<endl;
   cin>>d;x2=d;
  cout<<setw(5)<<"vvedite y"<<endl;
   cin>>e;y2=e;
  cout<<setw(5)<<"vvedite z"<<endl;
   cin>>f;z2=f;
  p=1;
  return 0;
}

float sumiraz (float &x1, float &y1, float &z1, float &x2, float &y2, float &z2,float&p)  //Vuchislenie sumu i raznosti 2-x vektorov
{if (p==0) {cout<<"vvedite dannie \n";}
  else
  {
   float x3,y3,z3,x4,y4,z4;
   clrscr();
   x3=x1+x2;y3=y1+y2;z3=z1+z2;
   cout<<"summa ravna ("<<x3<<","<<y3<<","<<z3<<") \n";
   x4=x1-x2;y4=y1-y2; z4=z1-z2;
   cout<<"raznost' ravna ("<<x4<<","<<y4<<","<<z4<<") \n";
   };
  return  0;
}

float skalpr (float &x1, float &y1, float &z1, float &x2, float &y2, float &z2,float &p) //Skaliarnoe proizvedenie
{if (p==0) {cout<<"vvedite dannie \n";}
  else
  {
   float sp=x1*x2+y1*y2+z1*z2;
   cout<<endl<<setw(4)<<"Skaliarnoe proizvedenie =  "<<sp<<endl;
   };
 return 0;
}

float vekpr(float &x1, float &y1, float &z1, float &x2, float &y2, float &z2,float &p) //Skaliarnoe proizvedenie
{if (p==0) {cout<<"vvedite dannie \n";}
  else
   {float x3=y1*z2-y2*z1;
    float y3=x1*z2-x2*z1;
    float z3=x1*y2-x2*y1;
    cout<<setw(4)<<"vektornoe proizvedenie vectorov = ("<<x3<<","<<y3<<","<<z3<<") \n";
    };
 return 0;
}

void main ()
{float (*v[4])(float &,float &,float &,float &,float &,float &,float &)={zadacha,sumiraz,skalpr,vekpr};
 char m[20];
 float z1,z2,x1,x2,y1,y2,p=0;
 int z,i;
 for (;;)
 {clrscr();
  cout<<endl<<setw(15)<<"funkcii raboti s dvumya 3x-mernumi vektorami  \n"
            <<"1, - vvesti koordinati vektorov \n"
            <<"2, - summa i raznost' vektorov \n"
            <<"3, - skaliarnoe proizvedenie vektorov \n"
            <<"4, - vektornoe proizvedenie vektorov \n"
            <<"5, - vihod iz programmu \n";
   for(;;)
   {cin>>m;
    z = atoi(m);
    if (z>=0 && z<6)
      {break;}
     else {cout<<"Vvedite vernoe znachenie N ot 1 do 5!";}
   }
   if (z==5)
     {break;}
   else
    {for (i=0;i<=4;i++)
      {if (z==i+1)
	     {(*v[i])(x1,x2,y1,y2,z1,z2,p);break;}
       }
    }
 getch();
 }
}