test/yosupo-judge/cartesian_tree/main.test.cpp

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• Last update: 2021-04-23 23:44:44+09:00
• Problem: https://judge.yosupo.jp/problem/cartesian_tree
• Link: View error logs on GitHub Actions

Depends on

• Cartesian tree (Mylib/Algorithm/cartesian_tree.cpp)
• Input vector (Mylib/IO/input_vector.cpp)
• join function (Mylib/IO/join.cpp)

Code

#define PROBLEM "https://judge.yosupo.jp/problem/cartesian_tree"

#include <functional>
#include <iostream>
#include <tuple>
#include "Mylib/Algorithm/cartesian_tree.cpp"
#include "Mylib/IO/input_vector.cpp"
#include "Mylib/IO/join.cpp"

namespace hl = haar_lib;

int main() {
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);

  int N;
  std::cin >> N;
  auto a = hl::input_vector<int>(N);

  auto ans = std::get<1>(hl::cartesian_tree(a, std::less<>()));

  for (int i = 0; i < N; ++i) {
    std::cout << ans[i].value_or(i) << "\n";
  }

  return 0;
}

#line 1 "test/yosupo-judge/cartesian_tree/main.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/cartesian_tree"

#include <functional>
#include <iostream>
#include <tuple>
#line 2 "Mylib/Algorithm/cartesian_tree.cpp"
#include <optional>
#line 4 "Mylib/Algorithm/cartesian_tree.cpp"
#include <vector>

namespace haar_lib {
  template <typename T, typename Compare>
  auto cartesian_tree(const std::vector<T> &a, Compare compare) -> std::tuple<
      int,                              // root
      std::vector<std::optional<int>>,  // parent nodes
      std::vector<std::optional<int>>,  // left nodes
      std::vector<std::optional<int>>   // right nodes
      > {
    const int n = a.size();
    std::vector<std::optional<int>> p(n), l(n), r(n);
    int root = 0;

    for (int i = 0; i < n; ++i) {
      if (i == 0) {
        continue;
      }

      int j = i - 1;

      while (1) {
        if (compare(a[i], a[j])) {
          if (not p[j]) {
            p[j] = i;
            l[i] = j;
            root = i;
            break;
          }

          j = *p[j];
          continue;
        }

        auto t = r[j];
        r[j]   = i;
        p[i]   = j;

        l[i] = t;
        if (t) p[*t] = i;

        break;
      }
    }

    return std::make_tuple(root, p, l, r);
  }
}  // namespace haar_lib
#line 4 "Mylib/IO/input_vector.cpp"

namespace haar_lib {
  template <typename T>
  std::vector<T> input_vector(int N) {
    std::vector<T> ret(N);
    for (int i = 0; i < N; ++i) std::cin >> ret[i];
    return ret;
  }

  template <typename T>
  std::vector<std::vector<T>> input_vector(int N, int M) {
    std::vector<std::vector<T>> ret(N);
    for (int i = 0; i < N; ++i) ret[i] = input_vector<T>(M);
    return ret;
  }
}  // namespace haar_lib
#line 3 "Mylib/IO/join.cpp"
#include <sstream>
#include <string>

namespace haar_lib {
  template <typename Iter>
  std::string join(Iter first, Iter last, std::string delim = " ") {
    std::stringstream s;

    for (auto it = first; it != last; ++it) {
      if (it != first) s << delim;
      s << *it;
    }

    return s.str();
  }
}  // namespace haar_lib
#line 9 "test/yosupo-judge/cartesian_tree/main.test.cpp"

namespace hl = haar_lib;

int main() {
  std::cin.tie(0);
  std::ios::sync_with_stdio(false);

  int N;
  std::cin >> N;
  auto a = hl::input_vector<int>(N);

  auto ans = std::get<1>(hl::cartesian_tree(a, std::less<>()));

  for (int i = 0; i < N; ++i) {
    std::cout << ans[i].value_or(i) << "\n";
  }

  return 0;
}

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