verify/LibraryChecker/math/number-theory/SternBrocotTree.test.cpp

View this file on GitHub
Last update: 2025-10-30 23:04:46+09:00
Problem: https://judge.yosupo.jp/problem/stern_brocot_tree

Depends on

Code

#include "../../../../template/template.hpp"
#define PROBLEM "https://judge.yosupo.jp/problem/stern_brocot_tree"
#include "../../../../math/number-theory/SternBrocotTree.hpp"

int main() {
    cin.tie(0)->sync_with_stdio(0);
    int t;
    in(t);
    rep(i, t) {
        string q;
        in(q);
        if (q == "ENCODE_PATH") {
            int a, b;
            in(a, b);
            auto res = encode_path(a, b);
            if (res.empty()) {
                out(0);
            } else {
                cout << res.size() << " ";
                rep(j, res.size()) {
                    cout << res[j].first << " " << res[j].second;
                    if (j + 1 != res.size()) {
                        cout << " ";
                    } else {
                        cout << "\n";
                    }
                }
            }
        } else if (q == "DECODE_PATH") {
            int k;
            in(k);
            vector<pair<char, int>> path(k);
            rep(j, k) {
                in(path[j].first, path[j].second);
            }
            auto res = decode_path(path);
            out(res.first, res.second);
        } else if (q == "LCA") {
            int a, b, c, d;
            in(a, b, c, d);
            auto res = sbt_lca(a, b, c, d);
            out(res.first, res.second);
        } else if (q == "ANCESTOR") {
            int k, a, b;
            in(k, a, b);
            auto res = sbt_ancestor(k, a, b);
            if (res.first == -1) {
                out(-1);
            } else {
                out(res.first, res.second);
            }
        } else {
            int a, b;
            in(a, b);
            auto res = sbt_range(a, b);
            out(res[0].first, res[0].second, res[1].first, res[1].second);
        }
    }
}

#line 2 "template/template.hpp"
#pragma region Macros
#include <bits/stdc++.h>
using namespace std;
using lint = long long;
using ull = unsigned long long;
using ld = long double;
using int128 = __int128_t;
#define all(x) (x).begin(), (x).end()
#define uniqv(v) v.erase(unique(all(v)), v.end())
#define OVERLOAD_REP(_1, _2, _3, name, ...) name
#define REP1(i, n) for (auto i = std::decay_t<decltype(n)>{}; (i) != (n); ++(i))
#define REP2(i, l, r) for (auto i = (l); (i) != (r); ++(i))
#define rep(...) OVERLOAD_REP(__VA_ARGS__, REP2, REP1)(__VA_ARGS__)
#define logfixed(x) cout << fixed << setprecision(10) << x << endl;

ostream &operator<<(ostream &dest, __int128_t value) {
  ostream::sentry s(dest);
  if (s) {
    __uint128_t tmp = value < 0 ? -value : value;
    char buffer[128];
    char *d = end(buffer);
    do {
      --d;
      *d = "0123456789"[tmp % 10];
      tmp /= 10;
    } while (tmp != 0);
    if (value < 0) {
      --d;
      *d = '-';
    }
    int len = end(buffer) - d;
    if (dest.rdbuf()->sputn(d, len) != len) {
      dest.setstate(ios_base::badbit);
    }
  }
  return dest;
}

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 != (int)v.size() ? " " : "");
  }
  return os;
}

template <typename T>
ostream &operator<<(ostream &os, const set<T> &set_var) {
  for (auto itr = set_var.begin(); itr != set_var.end(); itr++) {
    os << *itr;
    ++itr;
    if (itr != set_var.end()) os << " ";
    itr--;
  }
  return os;
}

template <typename T>
ostream &operator<<(ostream &os, const unordered_set<T> &set_var) {
  for (auto itr = set_var.begin(); itr != set_var.end(); itr++) {
    os << *itr;
    ++itr;
    if (itr != set_var.end()) os << " ";
    itr--;
  }
  return os;
}

template <typename T, typename U>
ostream &operator<<(ostream &os, const map<T, U> &map_var) {
  for (auto itr = map_var.begin(); itr != map_var.end(); itr++) {
    os << itr->first << " -> " << itr->second << "\n";
  }
  return os;
}

template <typename T, typename U>
ostream &operator<<(ostream &os, const unordered_map<T, U> &map_var) {
  for (auto itr = map_var.begin(); itr != map_var.end(); itr++) {
    os << itr->first << " -> " << itr->second << "\n";
  }
  return os;
}

template <typename T, typename U>
ostream &operator<<(ostream &os, const pair<T, U> &pair_var) {
  os << pair_var.first << " " << pair_var.second;
  return os;
}

void out() { cout << '\n'; }
template <class T, class... Ts>
void out(const T &a, const Ts &...b) {
  cout << a;
  (cout << ... << (cout << ' ', b));
  cout << '\n';
}

void outf() { cout << '\n'; }
template <class T, class... Ts>
void outf(const T &a, const Ts &...b) {
  cout << fixed << setprecision(14) << a;
  (cout << ... << (cout << ' ', b));
  cout << '\n';
}

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

inline void in(void) { return; }
template <typename First, typename... Rest>
void in(First &first, Rest &...rest) {
  cin >> first;
  in(rest...);
  return;
}

template <typename T>
bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <typename T>
bool chmin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}

vector<lint> dx8 = {1, 1, 0, -1, -1, -1, 0, 1};
vector<lint> dy8 = {0, 1, 1, 1, 0, -1, -1, -1};
vector<lint> dx4 = {1, 0, -1, 0};
vector<lint> dy4 = {0, 1, 0, -1};

#pragma endregion
#line 2 "verify/LibraryChecker/math/number-theory/SternBrocotTree.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/stern_brocot_tree"
#line 1 "math/number-theory/SternBrocotTree.hpp"

// m/n
vector<pair<char, int>> encode_path(lint m, lint n) {
    vector<pair<char, int>> res;
    while (m != 1 or n != 1) {
        if (m < n) {
            int num = (n - 1) / m;
            res.emplace_back('L', num);
            n -= m * num;
        } else {
            int num = (m - 1) / n;
            res.emplace_back('R', num);
            m -= n * num;
        }
    }
    return res;
}

pair<long long, long long> decode_path(const vector<pair<char, int>>& path) {
    long long n = 1;
    long long m = 0;
    long long n_ = 0;
    long long m_ = 1;
    if (path.empty()) return {1, 1};
    for (const auto [c, num] : path) {
        if (c == 'L') {
            n_ += n * num;
            m_ += m * num;
        } else {
            n += n_ * num;
            m += m_ * num;
        }
    }

    return {m + m_, n + n_};
}

// a/b, c/d
pair<long long, long long> sbt_lca(long long a, long long b, long long c, long long d) {
    vector<pair<char, int>> p1 = encode_path(a, b);
    vector<pair<char, int>> p2 = encode_path(c, d);
    int siz = min(int(p1.size()), int(p2.size()));
    if (siz == 0) return {1, 1};
    long long n = 1;
    long long m = 0;
    long long n_ = 0;
    long long m_ = 1;
    for (int i = 0; i < siz; i++) {
        if (p1[i].first != p2[i].first) {
            break;
        } else {
            long long num = min(p1[i].second, p2[i].second);
            if (p1[i].first == 'L') {
                n_ += n * num;
                m_ += m * num;
            } else {
                n += n_ * num;
                m += m_ * num;
            }
            if (p1[i].second != p2[i].second) break;
        }
    }

    return {m + m_, n + n_};
}

// a/b
pair<long long, long long> sbt_ancestor(int k, long long a, long long b) {
    vector<pair<char, int>> path = encode_path(a, b);
    long long n = 1;
    long long m = 0;
    long long n_ = 0;
    long long m_ = 1;
    for (auto [c, num] : path) {
        long long len = min(k, num);
        if (c == 'L') {
            n_ += n * len;
            m_ += m * len;
        } else {
            n += n_ * len;
            m += m_ * len;
        }
        k -= len;
        if (k == 0) break;
    }
    if (k == 0) {
        return {m + m_, n + n_};
    } else {
        return {-1, 1};
    }
}

vector<pair<long long, long long>> sbt_range(long long a, long long b) {
    vector<pair<char, int>> path = encode_path(a, b);
    long long n = 1;
    long long m = 0;
    long long n_ = 0;
    long long m_ = 1;

    if (path.empty()) return {{0, 1}, {1, 0}};
    for (const auto [c, num] : path) {
        if (c == 'L') {
            n_ += n * num;
            m_ += m * num;
        } else {
            n += n_ * num;
            m += m_ * num;
        }
    }
    return {{m, n}, {m_, n_}};
}
#line 4 "verify/LibraryChecker/math/number-theory/SternBrocotTree.test.cpp"

int main() {
    cin.tie(0)->sync_with_stdio(0);
    int t;
    in(t);
    rep(i, t) {
        string q;
        in(q);
        if (q == "ENCODE_PATH") {
            int a, b;
            in(a, b);
            auto res = encode_path(a, b);
            if (res.empty()) {
                out(0);
            } else {
                cout << res.size() << " ";
                rep(j, res.size()) {
                    cout << res[j].first << " " << res[j].second;
                    if (j + 1 != res.size()) {
                        cout << " ";
                    } else {
                        cout << "\n";
                    }
                }
            }
        } else if (q == "DECODE_PATH") {
            int k;
            in(k);
            vector<pair<char, int>> path(k);
            rep(j, k) {
                in(path[j].first, path[j].second);
            }
            auto res = decode_path(path);
            out(res.first, res.second);
        } else if (q == "LCA") {
            int a, b, c, d;
            in(a, b, c, d);
            auto res = sbt_lca(a, b, c, d);
            out(res.first, res.second);
        } else if (q == "ANCESTOR") {
            int k, a, b;
            in(k, a, b);
            auto res = sbt_ancestor(k, a, b);
            if (res.first == -1) {
                out(-1);
            } else {
                out(res.first, res.second);
            }
        } else {
            int a, b;
            in(a, b);
            auto res = sbt_range(a, b);
            out(res[0].first, res[0].second, res[1].first, res[1].second);
        }
    }
}