verify/yosupo/yosupo_shortest_path.test.cpp

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• Last update: 2024-11-25 14:08:01+09:00
• Problem: https://judge.yosupo.jp/problem/shortest_path

Depends on

• graph/dijkstra.hpp

Code

#define PROBLEM "https://judge.yosupo.jp/problem/shortest_path"

#include <bits/stdc++.h>
using namespace std;

#include "../../graph/dijkstra.hpp"

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int N, M, s, t;
    cin >> N >> M >> s >> t;

    vector<vector<pair<int, long long>>> G(N);
    
    for(int i = 0; i < M; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        G[a].push_back({b, c});
    }

    Dijkstra dij;

    auto dist = dij.solve(G, s);

    if(dist[t] == -1) {
        cout << -1 << endl;
        return 0;
    }

    auto path = dij.calc_path(t);

    cout << dist[t] << " " << path.size() - 1 << endl;
    for(int i = 0; i < (int)path.size() - 1; i++) {
        cout << path[i] << " " << path[i + 1] << endl;
    }

    return 0;
}

#line 1 "verify/yosupo/yosupo_shortest_path.test.cpp"
#define PROBLEM "https://judge.yosupo.jp/problem/shortest_path"

#include <bits/stdc++.h>
using namespace std;

#line 1 "graph/dijkstra.hpp"
struct Dijkstra{
    static constexpr long long INF = 2e18;
    vector<long long> dist;
    vector<int> pre;

    vector<long long> solve(const vector<vector<pair<int, long long>>>& G, int s) {
        dist.resize(G.size(), INF);
        pre.resize(G.size(), -1);
        dist[s] = 0;
        priority_queue<pair<long long, int>> pq;
        pq.push({0, s});
        while(pq.size()) {
            auto [d, v] = pq.top(); pq.pop();
            if(dist[v] < -d) continue;
            for(auto [nv, c] : G[v]) {
                if(dist[nv] <= dist[v] + c) continue;
                dist[nv] = dist[v] + c;
                pre[nv] = v;
                pq.push({-dist[nv], nv});
            }
        }
        for(int i = 0; i < (int)G.size(); i++) {
            if(dist[i] == INF) dist[i] = -1;
        }
        return dist;
    }

    vector<int> calc_path(int t) {
        vector<int> path;
        for(; t != -1; t = pre[t]) path.push_back(t);
        reverse(path.begin(), path.end());
        return path;
    }
};
#line 7 "verify/yosupo/yosupo_shortest_path.test.cpp"

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int N, M, s, t;
    cin >> N >> M >> s >> t;

    vector<vector<pair<int, long long>>> G(N);
    
    for(int i = 0; i < M; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        G[a].push_back({b, c});
    }

    Dijkstra dij;

    auto dist = dij.solve(G, s);

    if(dist[t] == -1) {
        cout << -1 << endl;
        return 0;
    }

    auto path = dij.calc_path(t);

    cout << dist[t] << " " << path.size() - 1 << endl;
    for(int i = 0; i < (int)path.size() - 1; i++) {
        cout << path[i] << " " << path[i + 1] << endl;
    }

    return 0;
}

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