need help, C++ set operations calculator - c++

Question

I'm currently trying to make a set operations calculator using c++ and I am still quite new to this language, I've basically finished the code(with the help of a few friends and google ofc), but I am required to have at least five sets instead of two for every operation except the complement of a set, I don't really know how to edit this to include five sets without ruining the code, it would be great if you guys could help me, thank you so much
here's the code:
#include <iostream>
void menu ();
void unionofsets();
void intersectionofsets();
void differenceofsets();
void complementofset();
void exit ();
using namespace std;
int main (){
char ch='y';
while(ch=='y')
{
menu ();
int choice;
cout <<"Please enter the operation you want here:";
cin >>choice;
switch (choice){
case 1:
unionofsets();
break;
case 2:
intersectionofsets();
break;
case 3:
differenceofsets();
break;
case 4:
complementofset();
break;
case 5:
exit ();
break;
default :
cout <<"The system encountered some errors, please try again.......\n Thank you.";
}
cout<<"\n Do you want to continue(yes(y)/no(n))";
cin>>ch;
}
return 0;
}
void menu ()
{
cout <<"Please select an operation by entering it's corresponding number.\n";
cout <<"1.Union of Two Sets"<<endl;
cout <<"----------------------\n";
cout <<"2.Intersection of Two Sets"<<endl;
cout <<"----------------------\n";
cout <<"3.Difference of Two Sets"<<endl;
cout <<"----------------------\n";
cout <<"4.Complement of a Given Set"<<endl;
cout <<"----------------------\n";
cout <<"5.Exit the Program"<<endl;
}
void unionofsets()
{
int size1,size2;
int set1[30];
int set2[30];
cout <<"You've selected to find the Union of two sets.\n";
cout <<"Enter the number of elements in the first set:";
cin >>size1;
cout <<"Enter the number of elements in the second set:";
cin >>size2;
cout <<"Enter "<<size1 <<" elements for first set:";
for (int i=0;i<size1;i++)
{
cin >>set1[i];
}
cout <<"Enter "<<size2<<" elements for the second set:";
for (int j=0;j<size2;j++)
{
cin >>set2[j];
}
cout <<"The union of set 1 and set 2 = {";
int k;
for (int a=0;a<size1;a++)
{
cout <<set1[a]<<" ,";
}
for (int i=0;i<size2;i++)
{
for (k=0;k<size1;k++)
{
if (set2[i]==set1[k])
{
break;
}
}
if (k==size1)
{
cout<<set2[i]<<" ,";
}
}
cout <<"}";
cout<<"\n-------------------------------------------------------------------------- \n";
}
void intersectionofsets(){
int set1[20];
int set2[20];
int sizeofset1,sizeofset2;
cout <<"You've selected to find the intersection of two sets."<<endl;
cout <<"Enter the number of elements in first set:";
cin >>sizeofset1;
cout <<"Enter the number of elements in second set:";
cin >>sizeofset2;
cout <<"Enter "<<sizeofset1<<" elements for first set separated by spaces:";
cout <<endl;
for (int i=0;i<sizeofset1;i++)
{
cin>>set1[i];
}
cout <<"Now enter "<<sizeofset2<<" elements for second set precisely:";
cout <<endl;
for (int j=0;j<sizeofset2;j++)
{
cin>>set2[j];
}
cout<<"The intersection set of first and second set is :";
cout<<" { ";
for (int i=0;i<sizeofset1;i++)
{
for (int j=0;j<sizeofset2;j++)
{
if (set1[i]==set2[j])
cout <<set1[i]<<", ";
}
}
cout<<"}";
cout<<"\n-------------------------------------------------------------------------- \n";
}
void differenceofsets (){
int size1;
int size2;
int set1[34];
int set2[54];
cout <<"You've selected to find the difference of two sets.\n";
cout <<"Enter the number of elements in set1:";
cin >>size1;
cout <<"Enter the number of elements in set2:";
cin >>size2;
cout <<"Enter the elements for the first set:";
for (int i=0;i<size1;i++)
{
cin >>set1[i];
}
cout <<"Enter the elements for the second set:";
for (int k=0;k<size2;k++)
{
cin >>set2[k];
}
cout <<"The difference of two sets you have entered is {";
int l;
for (int i=0;i<size1;i++)
{
for (l=0;l<size2;l++)
{
if (set1[i]==set2[l]){
break;
}
}
if (l==size2)
cout <<set1[i]<<" ,";
}
cout<<"}";
cout<<"\n-------------------------------------------------------------------------- \n";
}
void complementofset(){
int sizefuni=30;
int sizefgiv;
int uniset[30];
int userset[30];
uniset[0]=0;
cout <<"You've selected to find the complement of a set.\n";
cout <<"The universal set for your set is suppose to be \n\n {";
for (int i=0;i<sizefuni;i++)
{
uniset[i]=uniset[0]+i;
cout <<uniset[i]<<" ,";
}
cout <<"}\n\n"<<endl;
cout<<"enter the size of set :";
cin>>sizefgiv;
cout <<"enter the element of the set to find the complement.";
for (int k=0;k<sizefgiv;k++)
{
cin >>userset[k];
}
int l;
cout <<"The complement of the given set is ={";
for (int i=0;i<sizefuni;i++)
{
for (l=0;l<sizefgiv;l++)
{
if (uniset[i]==userset[l]){
break;
}
}
if (l==sizefgiv)
cout <<uniset[i] <<" ,";
}
cout<<"}";
cout<<"\n-------------------------------------------------------------------------- \n";
}
void exit(){
cout <<"Thank you for using our software.";
}