DSU offline (Add - Delete - Query) - DnC

//Make CSP great again
//You're as beautiful as the day I lost you
//New year, best wishes
#include <bits/stdc++.h>
#define TASK "TESTCODE"
#define Log2(x) 31 - __builtin_clz(x)
using namespace std;
const int N = 1e5;
map<pair<int, int>, vector<int> > Map;
int n, q, a[N + 1], t[N + 1], x[N + 1], y[N + 1], lab[N + 1];
bool res[N + 1];
struct SegmentTree
{
    int Tree[4 * N + 1];
    void BuildTree(int v, int TreeL, int TreeR)
    {
        if (TreeL == TreeR)
        {
            if (t[TreeL] == 1)
            {
                Tree[v] = a[TreeL];
            }
            else
            {
                Tree[v] = 0;
            }
            return ;
        }
        int mid = (TreeL + TreeR)/2;
        BuildTree(v * 2, TreeL, mid);
        BuildTree(v * 2 + 1, mid + 1, TreeR);
        Tree[v] = max(Tree[2 * v], Tree[2 * v + 1]);
    }
    void update(int v, int TreeL, int TreeR, int pos, int val)
    {
        if (TreeL == TreeR)
        {
            Tree[v] = val;
            return ;
        }
        int mid = (TreeL + TreeR)/2;
        if (pos <= mid)
        {
            update(v * 2, TreeL, mid, pos, val);
        }
        else
        {
            update(v * 2 + 1, mid + 1, TreeR, pos, val);
        }
        Tree[v] = max(Tree[2 * v], Tree[2 * v + 1]);
    }
    int query(int v, int TreeL, int TreeR, int R)
    {
        if (Tree[v] < R)
        {
            return -1;
        }
        if (TreeL == TreeR)
        {
            return TreeL;
        }
        int mid = (TreeL + TreeR)/2;
        int t = query(v * 2, TreeL, mid, R);
        if (t == -1)
        {
            t = query(v * 2 + 1, mid + 1, TreeR, R);
        }
        return t;
    }
} Tree;
void read()
{
    cin >> n >> q;
    memset(lab, -1, sizeof(lab));
    for (int i = 1; i <= q; ++ i)
    {
        a[i] = q + 1;
        cin >> t[i] >> x[i] >> y[i];
        if (x[i] > y[i])
        {
            swap(x[i], y[i]);
        }
        if (t[i] == 1)
        {
            Map[ {x[i], y[i]}].push_back(i);
        }
        else if (t[i] == 2)
        {
            if (!Map[ {x[i], y[i]}].empty())
            {
                a[Map[ {x[i], y[i]}].back()] = i;
                Map[ {x[i], y[i]}].pop_back();
            }
        }
    }
    Tree.BuildTree(1, 1, q);
}
stack<tuple<int, int, int, int, int> > Stack;
void Undo(int s)
{
    while(Stack.size() > s)
    {
        int u, v, sz, i, k;
        tie(u, v, sz, i, k) = Stack.top();
        Stack.pop();
        Tree.update(1, 1, q, i, a[i]);
        if (k == 0)
        {
            continue;
        }
        lab[v] = -sz;
        lab[u] += sz;
    }
}
int FindSet(int u)
{
    return lab[u] < 0 ? u : FindSet(lab[u]);
}
void Unite(int i)
{
    int u = FindSet(x[i]);
    int v = FindSet(y[i]);
    Tree.update(1, 1, q, i, 0);
    if (u == v)
    {
        Stack.push(make_tuple(u, v, -lab[v], i, 0));
        return ;
    }
    if (lab[v] < lab[u])
    {
        swap(u, v);
    }
    Stack.push(make_tuple(u, v, -lab[v], i, 1));
    lab[u] += lab[v];
    lab[v] = u;
}
void Dnc(int L, int R)
{
    if (L > R)
    {
        return ;
    }
    int s = Stack.size();
    while (true)
    {
        int i = Tree.query(1, 1, q, R);
        if (i == -1 || i > L)
        {
            break;
        }
        Unite(i);
    }
    if (L == R)
    {
        if (t[L] == 3)
        {
            int u = FindSet(x[L]), v = FindSet(y[L]);
            res[L] = (u == v);
        }
        Undo(s);
        return ;
    }
    int mid = (L + R)/2;
    Dnc(L, mid);
    Dnc(mid + 1, R);
    Undo(s);
}
void solve()
{
    Dnc(1, q);
    for (int i = 1; i <= q; ++ i)
    {
        if (t[i] == 3)
        {
            cout << (res[i] ? "YES" : "NO") << '\n';
        }
    }
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    if (fopen(TASK".INP", "r"))
    {
        freopen(TASK".INP", "r", stdin);
        //freopen(TASK".OUT", "w", stdout);
    }
    int t = 1;
    bool typetest = false;
    if (typetest)
    {
        cin >> t;
    }
    for (int __ = 1; __ <= t; ++ __)
    {
        //cout << "Case " << __ << ": ";
        read();
        solve();
    }
}