#724257 (C++17) No.1787 Do Use Dynamic Tree

• 問題: No.1787 Do Use Dynamic Tree
• ユーザー: ei1333333
• 提出日時: 2021-12-15 17:39:51
• 言語: C++17 (gcc 13.3.0 + boost 1.87.0)
• 結果: AC
• 実行時間: 1,108 ms / 10,000 ms
• コード長: 10,715 bytes
• コンパイル時間: 2,073 ms
• コンパイル使用メモリ: 213,324 KB
• 最終ジャッジ日時: 2025-01-26 23:12:30
• ジャッジサーバーID （参考情報）: judge4 / judge1

ファイルパターン	結果
sample	AC * 2
other	AC * 38

ソースコード

/* O((N + Q) log^2 N) 解 */

#include<bits/stdc++.h>

using namespace std;

using int64 = long long;
//const int mod = 1e9 + 7;
const int mod = 998244353;

const int64 infll = (1LL << 62) - 1;
const int inf = (1 << 30) - 1;

struct IoSetup {
  IoSetup() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(10);
    cerr << fixed << setprecision(10);
  }
} iosetup;


template< typename T1, typename T2 >
ostream &operator<<(ostream &os, const pair< T1, T2 > &p) {
  os << p.first << " " << p.second;
  return os;
}

template< typename T1, typename T2 >
istream &operator>>(istream &is, pair< T1, T2 > &p) {
  is >> p.first >> p.second;
  return is;
}

template< typename T >
ostream &operator<<(ostream &os, const vector< T > &v) {
  for(int i = 0; i < (int) v.size(); i++) {
    os << v[i] << (i + 1 != v.size() ? " " : "");
  }
  return os;
}

template< typename T >
istream &operator>>(istream &is, vector< T > &v) {
  for(T &in: v) is >> in;
  return is;
}

template< typename T1, typename T2 >
inline bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

template< typename T1, typename T2 >
inline bool chmin(T1 &a, T2 b) { return a > b && (a = b, true); }

template< typename T = int64 >
vector< T > make_v(size_t a) {
  return vector< T >(a);
}

template< typename T, typename... Ts >
auto make_v(size_t a, Ts... ts) {
  return vector< decltype(make_v< T >(ts...)) >(a, make_v< T >(ts...));
}

template< typename T, typename V >
typename enable_if< is_class< T >::value == 0 >::type fill_v(T &t, const V &v) {
  t = v;
}

template< typename T, typename V >
typename enable_if< is_class< T >::value != 0 >::type fill_v(T &t, const V &v) {
  for(auto &e: t) fill_v(e, v);
}

template< typename F >
struct FixPoint : F {
  FixPoint(F &&f) : F(forward< F >(f)) {}

  template< typename... Args >
  decltype(auto) operator()(Args &&... args) const {
    return F::operator()(*this, forward< Args >(args)...);
  }
};

template< typename F >
inline decltype(auto) MFP(F &&f) {
  return FixPoint< F >{forward< F >(f)};
}

/**
 * @brief 何でもできるが遅いLCT
 */
template< typename T, template< typename > typename E >
struct SlowLinkCutTree {
private:
  struct Node {
    Node *l, *r, *p;
    T info;
    E< T > sum;

    bool is_root() const {
      return not p or (p->l != this and p->r != this);
    }

    explicit Node(const T &info)
        : info(info), l(nullptr), r(nullptr), p(nullptr) {}
  };

public:
  using NP = Node *;

private:
  const E< T > e;

  void rotr(NP t) {
    NP x = t->p, y = x->p;
    if((x->l = t->r)) t->r->p = x;
    t->r = x, x->p = t;
    update(x), update(t);
    if((t->p = y)) {
      if(y->l == x) y->l = t;
      if(y->r == x) y->r = t;
    }
  }

  void rotl(NP t) {
    NP x = t->p, y = x->p;
    if((x->r = t->l)) t->l->p = x;
    t->l = x, x->p = t;
    update(x), update(t);
    if((t->p = y)) {
      if(y->l == x) y->l = t;
      if(y->r == x) y->r = t;
    }
  }

public:
  SlowLinkCutTree() : e{E< T >()} {}

  const E< T > &get_sum(NP t) {
    return t ? t->sum : e;
  }

  void update(NP t) {
    t->sum.update(get_sum(t->l), t->info, get_sum(t->r));
  }

  void splay(NP t) {
    while(not t->is_root()) {
      NP q = t->p;
      if(q->is_root()) {
        if(q->l == t) rotr(t);
        else rotl(t);
      } else {
        NP r = q->p;
        if(r->l == q) {
          if(q->l == t) rotr(q), rotr(t);
          else rotl(t), rotr(t);
        } else {
          if(q->r == t) rotl(q), rotl(t);
          else rotr(t), rotl(t);
        }
      }
    }
  }

  NP expose(NP t) {
    NP rp = nullptr;
    for(NP cur = t; cur; cur = cur->p) {
      splay(cur);
      if(cur->r) cur->sum.add(cur->r->sum);
      cur->r = rp;
      if(cur->r) cur->sum.erase(cur->r->sum);
      update(cur);
      rp = cur;
    }
    splay(t);
    return rp;
  }

  void link(NP child, NP parent) {
    expose(parent);
    expose(child);
    child->p = parent;
    parent->r = child;
    update(parent);
  }

  void cut(NP child) {
    expose(child);
    NP parent = child->l;
    child->l = nullptr;
    parent->p = nullptr;
    update(child);
  }

  NP alloc(const T &info) {
    NP t = new Node(info);
    update(t);
    return t;
  }

  bool is_connected(NP u, NP v) {
    expose(u), expose(v);
    return u == v or u->p;
  }

  vector< NP > build(vector< T > &vs) {
    vector< NP > nodes(vs.size());
    for(int i = 0; i < (int) vs.size(); i++) {
      nodes[i] = alloc(vs[i]);
    }
    return nodes;
  }

  NP lca(NP u, NP v) {
    if(not is_connected(u, v)) return nullptr;
    expose(u);
    return expose(v);
  }

  void set_key(NP t, const T &v) {
    expose(t);
    t->info = move(v);
    update(t);
  }

  const E< T > &query(NP u) {
    expose(u);
    return get_sum(u);
  }

  E< T > query_subtree(NP u) {
    expose(u);
    NP l = u->l;
    u->l = nullptr;
    update(u);
    auto ret = u->sum;
    u->l = l;
    update(u);
    return ret;
  }
};


using T = int;
using pi = pair< T, T >;

// Heavy-edge の情報
struct Key {
  T v, idx;

  Key(T idx, T v) : v(v), idx(idx) {}
};

template< typename Key >
struct Sum {
  T p_ans, p_light, p_left;

  T c_ans, c_light, c_left;

  set< pi > que;

  // 単位元(キーの値はアクセスしないので未初期化でもよい
  Sum() : p_ans(-1), p_light(-1), p_left(-1), c_ans(-1), c_light(-1), c_left(-1) {
    que.emplace(-1, -1);
  }

  void update(const Sum &p, const Key &t, const Sum &c) {
    p_left = ~p.p_left ? p.p_left : t.v;
    if(p.p_light < t.v) {
      if(que.rbegin()->first < c.p_left) {
        p_light = c.p_light;
        p_ans = c.p_ans;
      } else if(~que.rbegin()->first) {
        p_light = ~c.p_left ? inf : que.rbegin()->first;
        p_ans = que.rbegin()->second;
      } else {
        p_light = -1;
        p_ans = t.idx;
      }
    } else {
      p_light = inf;
      p_ans = p.p_ans;
    }

    c_left = ~c.c_left ? c.c_left : t.v;
    if(c.c_light < t.v) {
      if(que.rbegin()->first < p.c_left) {
        c_light = p.c_light;
        c_ans = p.c_ans;
      } else if(~que.rbegin()->first) {
        c_light = ~p.c_left ? inf : que.rbegin()->first;
        c_ans = que.rbegin()->second;
      } else {
        c_light = -1;
        c_ans = t.idx;
      }
    } else {
      c_light = inf;
      c_ans = c.c_ans;
    }
  }

  void add(const Sum &ch) {
    que.emplace(ch.p_left, ch.p_ans);
  }

  void erase(const Sum &ch) {
    que.erase(make_pair(ch.p_left, ch.p_ans));
  }
};


using LCT = SlowLinkCutTree< Key, Sum >;

/**
 * @brief Scanner(高速入力)
 */
struct Scanner {
public:

  explicit Scanner(FILE *fp) : fp(fp) {}

  template< typename T, typename... E >
  void read(T &t, E &... e) {
    read_single(t);
    read(e...);
  }

private:
  static constexpr size_t line_size = 1 << 16;
  static constexpr size_t int_digits = 20;
  char line[line_size + 1] = {};
  FILE *fp = nullptr;
  char *st = line;
  char *ed = line;

  void read() {}

  static inline bool is_space(char c) {
    return c <= ' ';
  }

  void reread() {
    ptrdiff_t len = ed - st;
    memmove(line, st, len);
    char *tmp = line + len;
    ed = tmp + fread(tmp, 1, line_size - len, fp);
    *ed = 0;
    st = line;
  }

  void skip_space() {
    while(true) {
      if(st == ed) reread();
      while(*st && is_space(*st)) ++st;
      if(st != ed) return;
    }
  }

  template< typename T, enable_if_t< is_integral< T >::value, int > = 0 >
  void read_single(T &s) {
    skip_space();
    if(st + int_digits >= ed) reread();
    bool neg = false;
    if(is_signed< T >::value && *st == '-') {
      neg = true;
      ++st;
    }
    typename make_unsigned< T >::type y = *st++ - '0';
    while(*st >= '0') {
      y = 10 * y + *st++ - '0';
    }
    s = (neg ? -y : y);
  }

  template< typename T, enable_if_t< is_same< T, string >::value, int > = 0 >
  void read_single(T &s) {
    s = "";
    skip_space();
    while(true) {
      char *base = st;
      while(*st && !is_space(*st)) ++st;
      s += string(base, st);
      if(st != ed) return;
      reread();
    }
  }

  template< typename T >
  void read_single(vector< T > &s) {
    for(auto &d: s) read(d);
  }
};

/**
 * @brief Printer(高速出力)
 */
struct Printer {
public:
  explicit Printer(FILE *fp) : fp(fp) {}

  ~Printer() { flush(); }

  template< bool f = false, typename T, typename... E >
  void write(const T &t, const E &... e) {
    if(f) write_single(' ');
    write_single(t);
    write< true >(e...);
  }

  template< typename... T >
  void writeln(const T &...t) {
    write(t...);
    write_single('\n');
  }

  void flush() {
    fwrite(line, 1, st - line, fp);
    st = line;
  }

private:
  FILE *fp = nullptr;
  static constexpr size_t line_size = 1 << 16;
  static constexpr size_t int_digits = 20;
  char line[line_size + 1] = {};
  char small[32] = {};
  char *st = line;

  template< bool f = false >
  void write() {}

  void write_single(const char &t) {
    if(st + 1 >= line + line_size) flush();
    *st++ = t;
  }

  template< typename T, enable_if_t< is_integral< T >::value, int > = 0 >
  void write_single(T s) {
    if(st + int_digits >= line + line_size) flush();
    if(s == 0) {
      write_single('0');
      return;
    }
    if(s < 0) {
      write_single('-');
      s = -s;
    }
    char *mp = small + sizeof(small);
    typename make_unsigned< T >::type y = s;
    size_t len = 0;
    while(y > 0) {
      *--mp = y % 10 + '0';
      y /= 10;
      ++len;
    }
    memmove(st, mp, len);
    st += len;
  }

  void write_single(const string &s) {
    for(auto &c: s) write_single(c);
  }

  void write_single(const char *s) {
    while(*s != 0) write_single(*s++);
  }

  template< typename T >
  void write_single(const vector< T > &s) {
    for(size_t i = 0; i < s.size(); i++) {
      if(i) write_single(' ');
      write_single(s[i]);
    }
  }
};

int main() {
  Scanner in(stdin);
  Printer out(stdout);
  int N;
  in.read(N);
  vector< int > A(N);
  LCT lct;
  vector< LCT::NP > vs(N);
  for(int i = 0; i < N; i++) {
    A[i] = i;
    vs[i] = lct.alloc(Key(i + 1, A[i]));
  }
  vector< vector< int > > g(N);
  for(int i = 1; i < N; i++) {
    int a, b;
    in.read(a, b);
    --a, --b;
    g[a].emplace_back(b);
    g[b].emplace_back(a);
  }
  MFP([&](auto dfs, int idx, int par) -> void {
    for(auto to: g[idx]) {
      if(to != par) {
        lct.link(vs[to], vs[idx]);
        dfs(to, idx);
      }
    }
  })(0, -1);
  int Q;
  in.read(Q);
  int x = 0;
  while(Q--) {
    int u, v;
    in.read(u, v);
    --u, --v;
    (u += x) %= N;
    (v += x) %= N;
    swap(A[u], A[v]);
    lct.set_key(vs[v], Key(v + 1, A[v]));
    lct.set_key(vs[u], Key(u + 1, A[u]));
    out.writeln(x = lct.query(vs[u]).c_ans);
  }
}