STL

#include <bits/stdc++.h>
using namespace std;

void insert(set<int> &s,int x);

void print_contents(set<int> &s);

void erase(set<int> &s,int x);

int find(set<int> &s,int x);

int size(set<int> &s);

int main() {
    // your code goes here
    int t;
    cin>>t;
    while(t--)
    {
        set<int> s;
        int q;
        cin>>q;
        while(q--)
        {
            char c;
            cin>>c;
            if(c=='a')
            {
                int x;
                cin>>x;
                insert(s,x);
            }
            if(c=='b')
            {
                print_contents(s);
            }
            if(c=='c')
            {
                int x;
                cin>>x;
                erase(s,x);
            }
            if(c=='d')
            {
                int x;
                cin>>x;
                cout<<find(s,x)<<" ";
            }
                       if(c=='e')
                       cout<<size(s)<<" ";

        }
cout<<endl;
    }
    return 0;
}// } Driver Code Ends


/* You are required to complete below methods */

/*inserts an element x to the set s */
void insert(set<int> &s,int x)
{
    //Your code here
    s.insert(x);
}

/*prints the contents of the set s */
void print_contents(set<int> &s)
{
    //Your code here
   for(auto u:s) cout<<u<<" ";
 // for(auto i=s.begin();i!=s.end();i++)
  //  cout<<*i<<" ";
}

/*erases an element x from the set s */
void erase(set<int> &s,int x)
{
    //Your code here
    s.erase(x);
}

/*returns 1 if the element x is
present in set s else returns -1 */
int find(set<int> &s,int x)
{
    //Your code here
   // if(s.find()!=s.end()) return 1;
   if(s.count(x)==1) return 1;
   else  return -1;
}

/*returns the size of the set s */
int size(set<int> &s)
{
   //Your code here
   return s.size();
}