rcpl

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View the Project on GitHub ruthen71/rcpl

:heavy_check_mark: verify/aoj_grl/aoj_grl_1_b.test.cpp

Depends on

Code

#define PROBLEM "https://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_1_B"

#include <bits/stdc++.h>

#include "graph/bellman_ford.hpp"
#include "graph/read_graph.hpp"

int main() {
    int N, M, r;
    std::cin >> N >> M >> r;
    auto G = read_graph<int>(N, M, true, true, 0);
    std::vector<int> s = {r};
    const int INF = 1 << 30;
    auto [dist, par, root] = bellman_ford(G, s, INF);
    int ans = *std::min_element(dist.begin(), dist.end());
    if (ans == -INF) {
        std::cout << "NEGATIVE CYCLE" << '\n';
    } else {
        for (int i = 0; i < N; i++) {
            if (dist[i] == INF) {
                std::cout << "INF" << '\n';
            } else {
                std::cout << dist[i] << '\n';
            }
        }
    }
    return 0;
}
#line 1 "verify/aoj_grl/aoj_grl_1_b.test.cpp"
#define PROBLEM "https://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=GRL_1_B"

#include <bits/stdc++.h>

#line 2 "graph/bellman_ford.hpp"

#line 2 "graph/graph_template.hpp"

#line 4 "graph/graph_template.hpp"
template <class T> struct Edge {
    int from, to;
    T cost;
    int id;

    Edge() = default;
    Edge(int from, int to, T cost = 1, int id = -1) : from(from), to(to), cost(cost), id(id) {}

    friend std::ostream &operator<<(std::ostream &os, const Edge<T> &e) {
        // output format: "{ id : from -> to, cost }"
        return os << "{ " << e.id << " : " << e.from << " -> " << e.to << ", " << e.cost << " }";
    }
};

template <class T> using Edges = std::vector<Edge<T>>;
template <class T> using Graph = std::vector<std::vector<Edge<T>>>;
#line 4 "graph/bellman_ford.hpp"

template <class T>
std::tuple<std::vector<T>, std::vector<int>, std::vector<int>>  //
bellman_ford(Graph<T> &G, std::vector<int> &s, const T INF) {
    int N = (int)G.size();
    std::vector<T> dist(N, INF);
    std::vector<int> par(N, -1), root(N, -1);

    for (auto &v : s) {
        dist[v] = 0;
        root[v] = v;
    }
    int loop_count = 0;

    while (true) {
        loop_count++;
        bool update = false;
        for (int cur = 0; cur < N; cur++) {
            if (dist[cur] == INF) continue;
            for (auto &e : G[cur]) {
                T nd = std::max(-INF, dist[cur] + e.cost);
                if (dist[e.to] > nd) {
                    par[e.to] = cur;
                    root[e.to] = root[cur];
                    update = true;
                    if (loop_count >= N) nd = -INF;
                    dist[e.to] = nd;
                }
            }
        }
        if (!update) break;
    }
    return {dist, par, root};
}
#line 2 "graph/read_graph.hpp"

#line 4 "graph/read_graph.hpp"

template <class T> Graph<T> read_graph(const int n, const int m, const bool weight = false, const bool directed = false, const int offset = 1) {
    Graph<T> g(n);
    for (int i = 0; i < m; i++) {
        int a, b;
        std::cin >> a >> b;
        a -= offset, b -= offset;
        if (weight) {
            T c;
            std::cin >> c;
            if (!directed) g[b].push_back(Edge(b, a, c, i));
            g[a].push_back(Edge(a, b, c, i));
        } else {
            // c = 1
            if (!directed) g[b].push_back(Edge(b, a, T(1), i));
            g[a].push_back(Edge(a, b, T(1), i));
        }
    }
    return g;
}

template <class T> Graph<T> read_parent(const int n, const bool weight = false, const bool directed = false, const int offset = 1) {
    Graph<T> g(n);
    for (int i = 1; i < n; i++) {
        int p;
        std::cin >> p;
        p -= offset;
        if (weight) {
            T c;
            std::cin >> c;
            if (!directed) g[i].push_back(Edge(i, p, c, i - 1));
            g[p].push_back(Edge(p, i, c, i - 1));
        } else {
            // c = 1
            if (!directed) g[i].push_back(Edge(i, p, T(1), i - 1));
            g[p].push_back(Edge(p, i, T(1), i - 1));
        }
    }
    return g;
}

std::tuple<Graph<int>, std::vector<std::vector<int>>, std::vector<std::pair<int, int>>> read_grid(const int h, const int w, std::string rel = ".#") {
    std::vector<std::string> s(h);
    std::vector id(h, std::vector<int>(w, -1));
    std::vector<std::pair<int, int>> loc;
    int n = 0;
    for (int i = 0; i < h; i++) {
        std::cin >> s[i];
        for (int j = 0; j < w; j++) {
            if (s[i][j] == rel[1]) {
                id[i][j] = n++;
                loc.emplace_back(i, j);
            }
        }
    }
    int m = 0;
    Graph<int> g(n);
    for (int i = 0; i < h; i++) {
        for (int j = 0; j < w; j++) {
            if (s[i][j] == rel[1]) {
                if (i + 1 < h and s[i + 1][j] == rel[1]) {
                    g[id[i][j]].push_back(Edge(id[i][j], id[i + 1][j], 1, m));
                    g[id[i + 1][j]].push_back(Edge(id[i + 1][j], id[i][j], 1, m++));
                }
                if (j + 1 < w and s[i][j + 1] == rel[1]) {
                    g[id[i][j]].push_back(Edge(id[i][j], id[i][j + 1], 1, m));
                    g[id[i][j + 1]].push_back(Edge(id[i][j + 1], id[i][j], 1, m++));
                }
            }
        }
    }
    return {g, id, loc};
}
#line 7 "verify/aoj_grl/aoj_grl_1_b.test.cpp"

int main() {
    int N, M, r;
    std::cin >> N >> M >> r;
    auto G = read_graph<int>(N, M, true, true, 0);
    std::vector<int> s = {r};
    const int INF = 1 << 30;
    auto [dist, par, root] = bellman_ford(G, s, INF);
    int ans = *std::min_element(dist.begin(), dist.end());
    if (ans == -INF) {
        std::cout << "NEGATIVE CYCLE" << '\n';
    } else {
        for (int i = 0; i < N; i++) {
            if (dist[i] == INF) {
                std::cout << "INF" << '\n';
            } else {
                std::cout << dist[i] << '\n';
            }
        }
    }
    return 0;
}
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