Cod sursa(job #3265846)

Utilizator ShAwDoRneYNacu Gabriel ShAwDoRneY Data 3 ianuarie 2025 18:11:44
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.66 kb
#include <fstream>
#include <vector>
#include <set>

using namespace std;

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

void DIJKSTRA(int startNode, int noNodes, vector<vector<pair<int,int>>> &graph) {

    vector<int> distante(noNodes+1, 1e9);
    set<pair<int,int>> Q;
    distante[startNode] = 0;
    Q.insert({0, startNode});

    while(!Q.empty()) {

        auto it = Q.begin();

        int currentNode = it->second;
        int distanta = it->first;

        Q.erase(it);

        for(auto neighbor : graph[currentNode]) {

            int newNode = neighbor.first;
            int newDistance = neighbor.second;
            int totalDistance = distanta+newDistance;

            if(totalDistance < distante[newNode]) {

                auto f = Q.find({distante[newNode], newNode});

                if(f!=Q.end())
                    Q.erase(f);

                distante[newNode] = totalDistance;
                Q.insert({totalDistance, newNode});
            }
        }
    }

    for(int i=2; i<=noNodes; i++) {
        if(distante[i] == 1e9)
            fout << 0 << ' ';
        else
            fout << distante[i] << ' ';
    }
        

}

int main() {

    int noNodes, noEdges;
    fin >> noNodes >> noEdges;

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

    for(int i=1; i<=noEdges; i++) {
        int firstNode, secondNode, weight;
        fin >> firstNode >> secondNode >> weight;

        graph[firstNode].push_back({secondNode, weight});
        graph[secondNode].push_back({firstNode, weight});
    }

    DIJKSTRA(1, noNodes, graph);

    return 0;
}