Graph/topological_sort.hpp

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Last update: 2020-11-05 12:15:41+09:00
Include: #include "Graph/topological_sort.hpp"

Depends on

Graph/graph.hpp

Verified with

Verify/topological_sort.test.cpp

Code

#pragma once

#include "graph.hpp"

#include <algorithm>

template <class Cost = int>
struct TopologicalSort {
    Graph<Cost> graph;
    std::vector<bool> visited;
    std::vector<int> vs, id;

    explicit TopologicalSort(const Graph<Cost>& graph)
        : graph(graph), visited(graph.size(), false), id(graph.size()) {
        for (int v = 0; v < (int)graph.size(); ++v) dfs(v);
        std::reverse(vs.begin(), vs.end());

        for (int i = 0; i < (int)graph.size(); ++i) id[vs[i]] = i;
    }

    void dfs(int v) {
        if (visited[v]) return;
        visited[v] = true;
        for (const auto& e : graph[v]) dfs(e.dst);
        vs.push_back(v);
    }
};

#line 2 "Graph/topological_sort.hpp"

#line 2 "Graph/graph.hpp"

#include <vector>

template <class Cost = int>
struct Edge {
    int src, dst;
    Cost cost;

    Edge() = default;
    Edge(int src, int dst, Cost cost = 1)
        : src(src), dst(dst), cost(cost){};

    bool operator<(const Edge<Cost>& e) const { return cost < e.cost; }
    bool operator>(const Edge<Cost>& e) const { return cost > e.cost; }
};

template <class Cost = int>
struct Graph : public std::vector<std::vector<Edge<Cost>>> {
    using std::vector<std::vector<Edge<Cost>>>::vector;

    void span(bool direct, int src, int dst, Cost cost = 1) {
        (*this)[src].emplace_back(src, dst, cost);
        if (!direct) (*this)[dst].emplace_back(dst, src, cost);
    }
};
#line 4 "Graph/topological_sort.hpp"

#include <algorithm>

template <class Cost = int>
struct TopologicalSort {
    Graph<Cost> graph;
    std::vector<bool> visited;
    std::vector<int> vs, id;

    explicit TopologicalSort(const Graph<Cost>& graph)
        : graph(graph), visited(graph.size(), false), id(graph.size()) {
        for (int v = 0; v < (int)graph.size(); ++v) dfs(v);
        std::reverse(vs.begin(), vs.end());

        for (int i = 0; i < (int)graph.size(); ++i) id[vs[i]] = i;
    }

    void dfs(int v) {
        if (visited[v]) return;
        visited[v] = true;
        for (const auto& e : graph[v]) dfs(e.dst);
        vs.push_back(v);
    }
};