Graph + Disjoint Set Forest

#include <bits/stdc++.h>
#define TASK "LABYRINTH"
using namespace std;
const int N = 1e5;
bool unlocked[N + 1];
vector<int> Adj[N+1];
int n, m, k, x, y, Trace[N + 1];
char type;
void read()
{
   cin >> n >> m >> k;
   fill(unlocked, unlocked + n + 1, false);
   fill(Trace, Trace + n + 1, -1);
   for (int i = 1; i <= m; ++ i)
   {
       cin >> x >> y;
       Adj[x].push_back(y);
       Adj[y].push_back(x);
   }
}
int FindSet(int u)
{
    if (Trace[u] < 0)
    {
        return u;
    }
    return Trace[u] = FindSet(Trace[u]);
}
void Unite(int r, int s)
{
    if (Trace[s] < Trace[r])
    {
        swap(r, s);
    }
    Trace[r] += Trace[s];
    Trace[s] = r;
}
void solve()
{
   while (k--)
   {
       cin >> type;
       if (type == 'X')
       {
           cin >> x;
           unlocked[x] = true;
           for (int v : Adj[x])
           {
               if (unlocked[v])
               {
                   int r = FindSet(x), s = FindSet(v);
                   if (r != s)
                   {
                       Unite(r, s);
                   }
               }
           }
       }
       else
       {
           cin >> x >> y;
           int u = FindSet(x), v = FindSet(y);
           if (u == v)
           {
               cout << "Y";
           }
           else
           {
               cout << "N";
           }
       }
   }
}
int main()
{
   ios_base::sync_with_stdio(false);
   cin.tie(nullptr);
   freopen(TASK".INP", "r", stdin);
   freopen(TASK".OUT", "w", stdout);
   int t = 1;
   bool typetest = false;
   if (typetest)
   {
      cin >> t;
   }
   for (int __ = 1; __ <= t; ++ __)
   {
      read();
      solve();
   }
}