func_code_string: #include <bits/stdc++.h>   using namespace std;   const int MAXN = 200000;   struct Splay {     struct node {       node *fa, *ch[2];       int num, key, mx, mn, tg;     } pl[2 * MAXN + 5], *root, *NIL;     Splay() {       root = NIL = &pl[0];       NIL->ch[0] = NIL->ch[1] = NIL->fa = NIL;       NIL->mx = -MAXN, NIL->mn = MAXN, NIL->tg = 0;     }     void set_child(node *x, node *y, int d) {       if (x != NIL) x->ch[d] = y;       if (y != NIL) y->fa = x;     }     void pushdown(node *x) {       if (x->tg) {         if (x->ch[0] != NIL)           x->ch[0]->key += x->tg, x->ch[0]->mx += x->tg, x->ch[0]->mn += x->tg,               x->ch[0]->tg += x->tg;         if (x->ch[1] != NIL)           x->ch[1]->key += x->tg, x->ch[1]->mx += x->tg, x->ch[1]->mn += x->tg,               x->ch[1]->tg += x->tg;         x->tg = 0;       }     }     void pushup(node *x) {       x->mn = min(x->key, min(x->ch[0]->mn, x->ch[1]->mn));       x->mx = max(x->key, max(x->ch[0]->mx, x->ch[1]->mx));     }     void rotate(node *x) {       node *y = x->fa;       int d = (y->ch[1] == x);       pushdown(y), pushdown(x);       if (y->fa != NIL)         set_child(y->fa, x, y->fa->ch[1] == y);       else         x->fa = y->fa;       set_child(y, x->ch[!d], d);       set_child(x, y, !d);       if (y == root) root = x;       pushup(y);     }     void splay(node *x, node *rt) {       pushdown(x);       while (x->fa != rt) {         node *y = x->fa;         if (y->fa == rt)           rotate(x);         else {           if ((y->fa->ch[1] == y) == (y->ch[1] == x))             rotate(y);           else             rotate(x);           rotate(x);         }       }       pushup(x);     }     void debug(node *x) {       if (x == NIL) return;       pushdown(x);       debug(x->ch[0]);       printf( %d : %d %d %d | %d %d n , x - pl, x->ch[0] - pl, x->ch[1] - pl,              x->fa - pl, x->num, x->key);       debug(x->ch[1]);     }     int dist(node *x, node *y) {       if (x == y) return 0;       splay(x, NIL), splay(y, root);       if (x->ch[0] == y) {         int d = min(min(x->key, y->key), x->ch[0]->ch[1]->mn);         return x->key + y->key - 2 * d;       } else {         int d = min(min(x->key, y->key), x->ch[1]->ch[0]->mn);         return x->key + y->key - 2 * d;       }     }     node *query(node *x, int d) {       pushdown(x);       if (x->ch[1]->mn <= d && d <= x->ch[1]->mx)         return query(x->ch[1], d);       else if (x->key == d) {         splay(x, NIL);         return x;       } else         return query(x->ch[0], d);     }     node *prev(node *x, node *rt) {       splay(x, rt);       node *ret = x->ch[0];       while (ret->ch[1] != NIL) ret = ret->ch[1];       splay(ret, rt);       return ret;     }     node *next(node *x, node *rt) {       splay(x, rt);       node *ret = x->ch[1];       while (ret->ch[0] != NIL) ret = ret->ch[0];       splay(ret, rt);       return ret;     }   } T;   Splay::node *fir[MAXN + 5], *bac[MAXN + 5];   int n, m, root;   vector<int> G[MAXN + 5];   void addedge(int u, int v) { G[u].push_back(v); }   int dep[MAXN + 5], dfn[2 * MAXN + 5], dcnt;   void newnode(Splay::node *nw, int x, int k) {     nw->ch[0] = nw->ch[1] = nw->fa = T.NIL;     nw->num = x, nw->key = nw->mn = nw->mx = k, nw->tg = 0;   }   void dfs(int x) {     dfn[++dcnt] = x, fir[x] = bac[x] = &T.pl[dcnt],     newnode(&T.pl[dcnt], x, dep[x]);     for (int i = 0; i < G[x].size(); i++) {       int p = G[x][i];       dep[p] = dep[x] + 1, dfs(p);       dfn[++dcnt] = x, bac[x] = &T.pl[dcnt], newnode(&T.pl[dcnt], x, dep[x]);     }   }   Splay::node *build(int l, int r) {     if (l > r) return T.NIL;     int mid = (l + r) >> 1;     Splay::node *p = &T.pl[mid];     p->ch[0] = build(l, mid - 1);     if (p->ch[0] != T.NIL) p->ch[0]->fa = p;     p->ch[1] = build(mid + 1, r);     if (p->ch[1] != T.NIL) p->ch[1]->fa = p;     T.pushup(p);     return p;   }   bool tag[MAXN + 5];   int main() {     scanf( %d%d , &n, &m);     for (int i = 1; i <= n; i++) {       int l;       scanf( %d , &l);       for (int j = 1; j <= l; j++) {         int x;         scanf( %d , &x);         addedge(i, x);         tag[x] = true;       }     }     for (int i = 1; i <= n; i++)       if (!tag[i]) root = i;     newnode(&T.pl[++dcnt], 0, -1), dfs(root), newnode(&T.pl[++dcnt], 0, -1);     T.root = build(1, dcnt);     for (int i = 1; i <= m; i++) {       int op;       scanf( %d , &op);       if (op == 1) {         int v, u;         scanf( %d%d , &v, &u);         printf( %d n , T.dist(fir[v], fir[u]));       } else if (op == 2) {         int v, h;         scanf( %d%d , &v, &h);         T.splay(fir[v], T.NIL);         Splay::node *u = T.query(fir[v]->ch[0], fir[v]->key - h);         Splay::node *l = T.prev(fir[v], T.NIL), *r = T.next(bac[v], T.root);         if (bac[l->num] == r) bac[l->num] = l;         T.set_child(l, r->ch[1], 1);         Splay::node *p = r->ch[0];         newnode(r, u->num, u->key), r->ch[0] = p;         r->tg += 1 - h, T.pushdown(r), T.pushup(r);         T.next(bac[u->num], T.NIL), T.splay(bac[u->num], T.root);         bac[u->num] = r;         T.set_child(T.root->ch[0], r, 1);       } else if (op == 3) {         int k;         scanf( %d , &k);         printf( %d n , T.query(T.root, k)->num);       }     }     return 0;   }   