Cod sursa(job #3193957)

Utilizator Samoila_AlexandruSamoilaAlexandru Samoila_Alexandru Data 16 ianuarie 2024 11:46:50
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.44 kb
#include <fstream>
#include <climits>
#include <vector>
#include <queue>

using namespace std;

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

using pereche=pair<int, int>;
const int nMax=(int)5e4 + 5, valMax=INT_MAX;

int n, m, x, y, c, d[nMax];
vector<pereche> g[nMax];

void dijkstra(int start)
{
    priority_queue<pereche, vector<pereche>, greater<pereche> > pq;
    vector<bool> viz=vector<bool>(n+1, 0);

    for(int i=1; i<=n; i++)
        d[i]=valMax;

    d[start]=0;
    pq.push({d[start], start});

    while(!pq.empty())
    {
        int cost=pq.top().first;
        int nod=pq.top().second;

        pq.pop();

        if(!viz[nod])
        {

            viz[nod]=1;

            for(auto i: g[nod])
            {
                int nodNou=i.first;
                int costNou=i.second;

                if(d[nodNou] > d[nod] + costNou)
                {
                    d[nodNou]=d[nod] + costNou;

                    pq.push({d[nodNou], nodNou});
                }
            }

        }
    }
}

int main()
{
    ios_base::sync_with_stdio(false);
    fin.tie(0);

    fin>>n>>m;
    for(int i=0; i<m; i++)
    {
        fin>>x>>y>>c;
        g[x].push_back({y, c});
    }
    fin.close();

    dijkstra(1);

    for(int i=2; i<=n; i++)
        if(d[i] == valMax)
            fout<<0<<' ';
        else fout<<d[i]<<' ';


    fout.close();
    return 0;
}