プリム法 (lib/graph/prim.hpp)

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Last update: 2025-06-10 13:56:45+09:00
Include: #include "lib/graph/prim.hpp"

Depends on

重み付きグラフ (lib/graph/graph.hpp)

Verified with

test/aoj/grl/prim.test.cpp

Code

#pragma once
#include <functional>
#include <queue>
#include <vector>
#include "graph/graph.hpp"

/// @brief プリム法
template <class T>
std::vector<typename Graph<T>::edge_type> prim(const Graph<T> &g, int r = 0) {
    using _edge = typename Graph<T>::edge_type;
    std::vector<_edge> res;
    std::vector<bool> visited(g.size());
    visited[r] = true;
    std::priority_queue<_edge, std::vector<_edge>, std::greater<>> p_que;
    for (auto &e : g[r]) p_que.emplace(e);
    while (!p_que.empty()) {
        auto edge = p_que.top();
        p_que.pop();
        if (visited[edge.to()]) continue;
        visited[edge.to()] = true;
        res.emplace_back(edge);
        for (auto &e : g[edge.to()]) {
            if (!visited[e.to()]) p_que.emplace(e);
        }
    }
    return res;
}

Traceback (most recent call last):
  File "/home/runner/.local/lib/python3.12/site-packages/competitive_verifier/oj/resolver.py", line 291, in resolve
    bundled_code = language.bundle(path, basedir=basedir)
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/runner/.local/lib/python3.12/site-packages/competitive_verifier/oj/verify/languages/cplusplus.py", line 242, in bundle
    bundler.update(path)
  File "/home/runner/.local/lib/python3.12/site-packages/competitive_verifier/oj/verify/languages/cplusplus_bundle.py", line 479, in update
    self._resolve(pathlib.Path(included), included_from=path)
  File "/home/runner/.local/lib/python3.12/site-packages/competitive_verifier/oj/verify/languages/cplusplus_bundle.py", line 286, in _resolve
    raise BundleErrorAt(path, -1, "no such header")
competitive_verifier.oj.verify.languages.cplusplus_bundle.BundleErrorAt: graph/graph.hpp: line -1: no such header