Cod sursa(job #3264497)

Utilizator BogdancxTrifan Bogdan Bogdancx Data 21 decembrie 2024 18:18:15
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.48 kb
#include <algorithm>
#include <vector>
#include <iostream>
#include <fstream>
#include <queue>
#include <climits>

using namespace std;

vector<int> Dijkstra(int start, const vector<vector<pair<int, int>>>& graph)
{
    priority_queue<pair<int, int>, vector<pair<int, int>>, greater<pair<int, int>>> pq;
    vector<int> dist(graph.size(), INT_MAX);

    dist[start] = 0;
    pq.emplace(dist[start], start);

    while(!pq.empty())
    {
        int node = pq.top().second;
        int d = pq.top().first;
        pq.pop();

        for(auto [neigh, cost]: graph[node])
        {
            int new_d = d + cost;

            if(new_d < dist[neigh])
            {
                dist[neigh] = new_d;
                pq.emplace(new_d, neigh);
            }
        }
    }
    return dist;
}

int main()
{
    ios::sync_with_stdio(false);  // Fast input/output
    cin.tie(nullptr);             // Untie cin from cout to optimize IO operations

    ifstream fin("dijkstra.in");
    ofstream fout("dijkstra.out");

    int n, m;

    fin >> n >> m;

    vector<vector<pair<int, int>>> graph(n + 1);

    for(int i = 0; i < m; i++)
    {
        int a, b, c;

        fin >> a >> b >> c;

        graph[a].emplace_back(b, c);
    }

    vector<int> result = Dijkstra(1, graph);

    for(int i = 2; i <= result.size() - 1; i++)
    {
        if(result[i] == INT_MAX) fout << 0 << ' ';
        else fout << result[i] << ' ';
    }

    return 0;
}