C++ Library for Competitive Programming
View the Project on GitHub emthrm/cp-library
/* * @title グラフ/トポロジカルソート * * verification-helper: IGNORE * verification-helper: PROBLEM http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_4_B */ #include <iostream> #include <vector> #include "emthrm/graph/edge.hpp" #include "emthrm/graph/topological_sort.hpp" int main() { int v, e; std::cin >> v >> e; std::vector<std::vector<emthrm::Edge<bool>>> graph(v); while (e--) { int s, t; std::cin >> s >> t; graph[s].emplace_back(s, t); } for (const int ans : emthrm::topological_sort(graph)) { std::cout << ans << '\n'; } return 0; }
#line 1 "test/graph/topological_sort.test.cpp" /* * @title グラフ/トポロジカルソート * * verification-helper: IGNORE * verification-helper: PROBLEM http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_4_B */ #include <iostream> #include <vector> #line 1 "include/emthrm/graph/edge.hpp" /** * @title 辺 */ #ifndef EMTHRM_GRAPH_EDGE_HPP_ #define EMTHRM_GRAPH_EDGE_HPP_ #include <compare> namespace emthrm { template <typename CostType> struct Edge { CostType cost; int src, dst; explicit Edge(const int src, const int dst, const CostType cost = 0) : cost(cost), src(src), dst(dst) {} auto operator<=>(const Edge& x) const = default; }; } // namespace emthrm #endif // EMTHRM_GRAPH_EDGE_HPP_ #line 1 "include/emthrm/graph/topological_sort.hpp" #include <queue> #include <ranges> #include <utility> #line 8 "include/emthrm/graph/topological_sort.hpp" #line 1 "include/emthrm/graph/edge.hpp" /** * @title 辺 */ #ifndef EMTHRM_GRAPH_EDGE_HPP_ #define EMTHRM_GRAPH_EDGE_HPP_ #include <compare> namespace emthrm { template <typename CostType> struct Edge { CostType cost; int src, dst; explicit Edge(const int src, const int dst, const CostType cost = 0) : cost(cost), src(src), dst(dst) {} auto operator<=>(const Edge& x) const = default; }; } // namespace emthrm #endif // EMTHRM_GRAPH_EDGE_HPP_ #line 10 "include/emthrm/graph/topological_sort.hpp" namespace emthrm { template <typename CostType> std::vector<int> topological_sort( const std::vector<std::vector<Edge<CostType>>>& graph) { const int n = graph.size(); std::vector<int> deg(n, 0); for (const int e : graph | std::views::join | std::views::transform(&Edge<CostType>::dst)) { ++deg[e]; } std::queue<int> que; for (int i = 0; i < n; ++i) { if (deg[i] == 0) que.emplace(i); } std::vector<int> res; res.reserve(n); while (!que.empty()) { const int ver = que.front(); que.pop(); res.emplace_back(ver); for (const int e : graph[ver] | std::views::transform(&Edge<CostType>::dst)) { if (--deg[e] == 0) que.emplace(e); } } return std::cmp_equal(res.size(), n) ? res : std::vector<int>{}; } } // namespace emthrm #line 13 "test/graph/topological_sort.test.cpp" int main() { int v, e; std::cin >> v >> e; std::vector<std::vector<emthrm::Edge<bool>>> graph(v); while (e--) { int s, t; std::cin >> s >> t; graph[s].emplace_back(s, t); } for (const int ans : emthrm::topological_sort(graph)) { std::cout << ans << '\n'; } return 0; }