tests/graph/topological_sort.notest.cpp

View this file on GitHub
Last update: 2024-04-04 16:06:20+09:00
Link: https://onlinejudge.u-aizu.ac.jp/problems/GRL_4_B

Depends on

Code

// 結果が一意でないため、テストは行わない
// #define PROBLEM "https://onlinejudge.u-aizu.ac.jp/problems/GRL_4_B"

#include <bits/stdc++.h>
#include "ugilib/base/constants.hpp"
#include "ugilib/base/definitions.hpp"
#include "ugilib/graph/topological_sort.hpp"

using namespace std;

// debug settings
// #define DEBUG
#ifdef DEBUG
// debug input
string _INPUT = R"(
5
1 2 3 4 5
)";
auto _cin = stringstream(_INPUT.substr(1)); // remove '\n' at _INPUT[0]
#else
// standard input
auto& _cin = cin;
#endif

// speed up
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

// reader
struct rd {
    // T
    template<typename T> static T i() { T x; _cin >> x; return x; }  // T item
    // vector<T>
    template<typename T> static vector<T> v(int n) {vector<T> v(n); rep(i, n) _cin >> v[i]; return v;}  // vector<T>
    // vector<pair<T, T>>
    template<typename T> static vector<pair<T, T>> vp(int n) {vector<pair<T, T>> v(n); rep(i, n) _cin >> v[i].first >> v[i].second; return v;}  // vector<pair<T, T>>
    // tuple
    template<typename... Args> static tuple<Args...> t() {
        tuple<Args...> values;
        apply([](auto&... args) { ((_cin >> args), ...); }, values);
        return values;
    }
};

// debug print utility
namespace deb {
    #include <cxxabi.h>
    // demangle type name
    string demangle(const char* name) {
        int status = -4;
        unique_ptr<char, void(*)(void*)> res{
            abi::__cxa_demangle(name, NULL, NULL, &status),
            free
        };
        return (status == 0) ? string(res.get()) : name ;
    }
    // meta functions for type traits
    template<typename T>
    constexpr bool isArithmeticContainer() { return is_arithmetic<typename T::value_type>::value; }
    // for SFINAE
    template<typename T, typename = void> struct has_key_and_mapped_type : false_type {};
    template<typename T> struct has_key_and_mapped_type<T, void_t<typename T::key_type, typename T::mapped_type>> : true_type {};
    // for map or unordered_map
    template<typename T>
    constexpr bool isMapLike() { return has_key_and_mapped_type<T>::value; }

    // for values
    template<typename T, typename enable_if<is_arithmetic<T>::value, nullptr_t>::type = nullptr>
    void p(const T& x) { cout << x << " "; }
    // for pairs
    template <typename T, typename S>
    void p(const pair<T, S>& _p){ p(_p.first); p(_p.second); cout << endl; }
    // for string
    void p(const string& s) { cout << s << endl; }
    // for containers
    template<typename T,  typename enable_if<!is_arithmetic<T>::value, nullptr_t>::type = nullptr>
    void p(const T& container) {
        // map and unordered_map
        if constexpr (isMapLike<T>()) {
            cout << demangle(typeid(T).name()) << ":" << endl;
            for (const auto& kv : container) {
                cout << "[" << kv.first << "] => ";
                p(kv.second);
                if constexpr (is_arithmetic_v<typename T::mapped_type>) cout << endl;
            }
        // vector or set or others
        } else {
            if constexpr (!isArithmeticContainer<T>()) cout << demangle(typeid(T).name()) << ":" << endl;
            for (auto it = begin(container); it != end(container); ++it) {
                p(*it);
            }
            if constexpr (isArithmeticContainer<T>()) cout << endl;
        }
    }
};  // namespace deb

int main() {
    auto& cin = _cin;
    // speed up io
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    // code
    auto [N, M] = rd::t<ll, ll>();
    vector<vector<int>> g(N);
    rep(i, M) {
        auto [x, y] = rd::t<int, int>();
        g[x].push_back(y);
    }

    vector<int> topology = ugilib::topological_sort(g);
    for (int node : topology) cout << node << endl;

    return 0;
}

#line 1 "tests/graph/topological_sort.notest.cpp"
// 結果が一意でないため、テストは行わない
// #define PROBLEM "https://onlinejudge.u-aizu.ac.jp/problems/GRL_4_B"

#include <bits/stdc++.h>
#line 2 "ugilib/base/definitions.hpp"

using ll = long long;
using ull = unsigned long long;
using ld = long double;
#define rep(i, n) for(size_t i = 0; i < n; i++)  // rep macro
#define all(v) begin(v), end(v)  // all iterator
#line 3 "ugilib/base/constants.hpp"

namespace ugilib::constants {
    template<typename T>
    inline constexpr T INF = std::numeric_limits<T>::max() / 2;
} // namespace ugilib::constants

const ll INF = ugilib::constants::INF<ll>;
#line 2 "ugilib/graph/topological_sort.hpp"

/**
 * @file topological_sort.hpp
 * @brief トポロジカルソート，入次数計算関数の定義
*/

#line 9 "ugilib/graph/topological_sort.hpp"
using namespace std;

namespace ugilib {
    /**
     * @brief DAGの各頂点の入次数を計算する
     * @tparam T 整数型
     * @param g 有向グラフ
     * @return vector<T> 入次数リスト
     * @note O(V + E)
     */
    template <typename T>
    vector<T> calc_indegrees(const vector<vector<T>> &g) {
        static_assert(is_integral<T>::value, "T must be integral type");
        vector<T> indeg(g.size(), 0);
        for (const vector<T> &edges_from_u : g) {
            for (const T &v : edges_from_u) {
                indeg[v]++;
            }
        }
        return indeg;
    }

    /**
     * @brief DAGのトポロジカルソート
     * @tparam T 整数型
     * @param g DAG
     * @return vector<T> トポロジカルソート結果
     * @note O(V + E)
    */
    template <typename T>
    vector<T> topological_sort(const vector<vector<T>> &g) {
        static_assert(is_integral<T>::value, "T must be integral type");
        // 入次数の計算
        vector<T> indegs = ugilib::calc_indegrees(g);

        // トポロジカル順序を決定する
        vector<T> topology;
        queue<T> start_nodes;
        for (size_t i = 0; i < indegs.size(); i++) {
            if (indegs[i] == 0) start_nodes.push(i);
        }
        while (!start_nodes.empty()) {
            // 入次数0の頂点の順序を確定
            T node = start_nodes.front(); start_nodes.pop();
            topology.push_back(node);

            // 頂点・辺を削除する
            for (const T &next : g[node]) {  // この頂点から出る全ての辺を削除
                if (--indegs[next] == 0) {  // それによって入次数が0になったら
                    start_nodes.push(next);  // 順序を確定できる
                }
            }
        }

        assert(topology.size() == g.size());  // DAGでない場合はトポロジカルソートできない
        return topology;
    }
}  // namespace ugilib
#line 8 "tests/graph/topological_sort.notest.cpp"

using namespace std;

// debug settings
// #define DEBUG
#ifdef DEBUG
// debug input
string _INPUT = R"(
5
1 2 3 4 5
)";
auto _cin = stringstream(_INPUT.substr(1)); // remove '\n' at _INPUT[0]
#else
// standard input
auto& _cin = cin;
#endif

// speed up
#pragma GCC target("avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")

// reader
struct rd {
    // T
    template<typename T> static T i() { T x; _cin >> x; return x; }  // T item
    // vector<T>
    template<typename T> static vector<T> v(int n) {vector<T> v(n); rep(i, n) _cin >> v[i]; return v;}  // vector<T>
    // vector<pair<T, T>>
    template<typename T> static vector<pair<T, T>> vp(int n) {vector<pair<T, T>> v(n); rep(i, n) _cin >> v[i].first >> v[i].second; return v;}  // vector<pair<T, T>>
    // tuple
    template<typename... Args> static tuple<Args...> t() {
        tuple<Args...> values;
        apply([](auto&... args) { ((_cin >> args), ...); }, values);
        return values;
    }
};

// debug print utility
namespace deb {
    #include <cxxabi.h>
    // demangle type name
    string demangle(const char* name) {
        int status = -4;
        unique_ptr<char, void(*)(void*)> res{
            abi::__cxa_demangle(name, NULL, NULL, &status),
            free
        };
        return (status == 0) ? string(res.get()) : name ;
    }
    // meta functions for type traits
    template<typename T>
    constexpr bool isArithmeticContainer() { return is_arithmetic<typename T::value_type>::value; }
    // for SFINAE
    template<typename T, typename = void> struct has_key_and_mapped_type : false_type {};
    template<typename T> struct has_key_and_mapped_type<T, void_t<typename T::key_type, typename T::mapped_type>> : true_type {};
    // for map or unordered_map
    template<typename T>
    constexpr bool isMapLike() { return has_key_and_mapped_type<T>::value; }

    // for values
    template<typename T, typename enable_if<is_arithmetic<T>::value, nullptr_t>::type = nullptr>
    void p(const T& x) { cout << x << " "; }
    // for pairs
    template <typename T, typename S>
    void p(const pair<T, S>& _p){ p(_p.first); p(_p.second); cout << endl; }
    // for string
    void p(const string& s) { cout << s << endl; }
    // for containers
    template<typename T,  typename enable_if<!is_arithmetic<T>::value, nullptr_t>::type = nullptr>
    void p(const T& container) {
        // map and unordered_map
        if constexpr (isMapLike<T>()) {
            cout << demangle(typeid(T).name()) << ":" << endl;
            for (const auto& kv : container) {
                cout << "[" << kv.first << "] => ";
                p(kv.second);
                if constexpr (is_arithmetic_v<typename T::mapped_type>) cout << endl;
            }
        // vector or set or others
        } else {
            if constexpr (!isArithmeticContainer<T>()) cout << demangle(typeid(T).name()) << ":" << endl;
            for (auto it = begin(container); it != end(container); ++it) {
                p(*it);
            }
            if constexpr (isArithmeticContainer<T>()) cout << endl;
        }
    }
};  // namespace deb

int main() {
    auto& cin = _cin;
    // speed up io
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    // code
    auto [N, M] = rd::t<ll, ll>();
    vector<vector<int>> g(N);
    rep(i, M) {
        auto [x, y] = rd::t<int, int>();
        g[x].push_back(y);
    }

    vector<int> topology = ugilib::topological_sort(g);
    for (int node : topology) cout << node << endl;

    return 0;
}