Перезапустить программу при неверном выборе в swich

#include <stdlib.h>   
#include <conio.h>
#include <iostream.h>
 
main()
{
srand(time(NULL));
     int n1,n2,s,x,p,c;
     cout<<"Vvedit rozmir  mass1 (do 50 sumvoliv)= ";
     cin>>n1;
     cout<<"Vvedit rozmir  mass2 (do 50 sumvoliv)= ";
     cin>>n2;
     int mass1[100],mass2[100];
     int *mass3[100];
     for (int i=0; i<n1;i++)
     mass1[i]=rand()%10;
     
     for (int j=0; j<n2;j++)
     mass2[j]=rand()%10;
     cout << "Vibirite deistvie:\n 1-vuved mass;\n 2-perece4enie;\n 3-obedinenie;\n 4-raznoct:\n ";
     cin >> s;
  switch (s) 
     {
            case 1: {
cout<<"1 masuv:"<<endl;
for (int i=0; i<n1;i++)
cout<<mass1[i]<<" ";
cout<<endl;
cout<<"2 masuv:"<<endl;
for (int j=0; j<n2;j++)
cout<<mass2[j]<<" ";break;
}
            case 2:{ 
    p=0;int *mass3 = new int[p];
    for (int i = 0; i < n1; i++)
    { 
        int j=0, k=0;
        while (mass2[j] != mass1[i] && j < n2) j++;
        while (mass3[k] != mass1[i] && k < p) k++;
        if (j != n2 && k == p) 
        {mass3[p++] = mass1[i];}
    }
cout<<"1 masuv:"<<endl;
for (int i=0; i<n1;i++)
cout<<mass1[i]<<" ";
cout<<endl;
cout<<"2 masuv:"<<endl;
for (int j=0; j<n2;j++)
cout<<mass2[j]<<" ";
cout<<endl;
cout<<"3 masuv:"<<endl;
for (int i=0; i<p; i++)
cout << mass3[i] << " ";break;
    } 
            case 3: { 
    x = n1 + n2;
    int *mass3 = new int[x];
    for (int i=0; i<n1; i++)
    {mass3[i] = mass1[i];}
    for (int i=n1; i<x; i++)
    {mass3[i] = mass2[i - n1];}
cout<<"1 masuv:"<<endl;
for (int i=0; i<n1;i++)
cout<<mass1[i]<<" ";
cout<<endl;
cout<<"2 masuv:"<<endl;
for (int j=0; j<n2;j++)
cout<<mass2[j]<<" ";
cout<<endl;   
cout<<"3 masuv:"<<endl;
for (int i=0; i<x; i++)
cout << mass3[i] << " ";break;
    }   
           case 4: { 
     c=0;int *mass3 = new int[c];
     for (int i=0; i<n1; i++)
    {
        int j=0, f=0;
        while (mass2[j]!=mass1[i] && j<n2) j++;
        while (mass3[f]!=mass1[i] && f<c) f++;
        if (j==n2 && f==c) mass3[c++] = mass1[i];
     }   
cout<<"1 masuv:"<<endl;
for (int i=0; i<n1;i++)
cout<<mass1[i]<<" ";
cout<<endl;
cout<<"2 masuv:"<<endl;
for (int j=0; j<n2;j++)
cout<<mass2[j]<<" ";
cout<<endl;
cout<<"3 masuv:"<<endl;
for (int i=0; i<c; i++)
cout << mass3[i] << " ";break;
    }
default: cout<<"Error"; 
}
  getch();
  return 0;       
}

#include <stdlib.h>   
#include <conio.h>
#include <iostream.h>
 
main()
{
srand(time(NULL));
     int n1,n2,s,x,p,c;
     cout<<"Vvedit rozmir  mass1 (do 50 sumvoliv)= ";
     cin>>n1;
     cout<<"Vvedit rozmir  mass2 (do 50 sumvoliv)= ";
     cin>>n2;
     int mass1[100],mass2[100];
     int *mass3[100];
     for (int i=0; i<n1;i++)
     mass1[i]=rand()%10;
     
     for (int j=0; j<n2;j++)
     mass2[j]=rand()%10;
 
int vychod = 1;
while(vychod)
{
     cout << "Vibirite deistvie:\n 1-vuved mass;\n 2-perece4enie;\n 3-obedinenie;\n 4-raznoct:\n ";
     cin >> s;
  switch (s) 
     {
            case 1: {
cout<<"1 masuv:"<<endl;
for (int i=0; i<n1;i++)
cout<<mass1[i]<<" ";
cout<<endl;
cout<<"2 masuv:"<<endl;
for (int j=0; j<n2;j++)
cout<<mass2[j]<<" ";break;
}
            case 2:{ 
    p=0;int *mass3 = new int[p];
    for (int i = 0; i < n1; i++)
    { 
        int j=0, k=0;
        while (mass2[j] != mass1[i] && j < n2) j++;
        while (mass3[k] != mass1[i] && k < p) k++;
        if (j != n2 && k == p) 
        {mass3[p++] = mass1[i];}
    }
cout<<"1 masuv:"<<endl;
for (int i=0; i<n1;i++)
cout<<mass1[i]<<" ";
cout<<endl;
cout<<"2 masuv:"<<endl;
for (int j=0; j<n2;j++)
cout<<mass2[j]<<" ";
cout<<endl;
cout<<"3 masuv:"<<endl;
for (int i=0; i<p; i++)
cout << mass3[i] << " ";break;
    } 
            case 3: { 
    x = n1 + n2;
    int *mass3 = new int[x];
    for (int i=0; i<n1; i++)
    {mass3[i] = mass1[i];}
    for (int i=n1; i<x; i++)
    {mass3[i] = mass2[i - n1];}
cout<<"1 masuv:"<<endl;
for (int i=0; i<n1;i++)
cout<<mass1[i]<<" ";
cout<<endl;
cout<<"2 masuv:"<<endl;
for (int j=0; j<n2;j++)
cout<<mass2[j]<<" ";
cout<<endl;   
cout<<"3 masuv:"<<endl;
for (int i=0; i<x; i++)
cout << mass3[i] << " ";break;
    }   
           case 4: { 
     c=0;int *mass3 = new int[c];
     for (int i=0; i<n1; i++)
    {
        int j=0, f=0;
        while (mass2[j]!=mass1[i] && j<n2) j++;
        while (mass3[f]!=mass1[i] && f<c) f++;
        if (j==n2 && f==c) mass3[c++] = mass1[i];
     }   
cout<<"1 masuv:"<<endl;
for (int i=0; i<n1;i++)
cout<<mass1[i]<<" ";
cout<<endl;
cout<<"2 masuv:"<<endl;
for (int j=0; j<n2;j++)
cout<<mass2[j]<<" ";
cout<<endl;
cout<<"3 masuv:"<<endl;
for (int i=0; i<c; i++)
cout << mass3[i] << " ";break;
    }
default:{ vychod = 0;} 
}
}
  getch();
  return 0;       
}