Cod sursa(job #2976333)

Utilizator Samoila_AlexandruSamoilaAlexandru Samoila_Alexandru Data 8 februarie 2023 22:57:23
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.48 kb
#include <fstream>
#include <vector>
#include <queue>
#include <climits>

using namespace std;

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

const int nMax=5e4+5;
using pereche=pair<int, int>;

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

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

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

    d[start]=0;
    pq.push({d[start], start});
    while(!pq.empty())
    {
        int cost=pq.top().first;
        int nod=pq.top().second;

        pq.pop();

        if(!v[nod])
        {
            v[nod]=1;

            for(vector<pair<int, int>>::iterator it=g[nod].begin(); it!=g[nod].end(); it++)
            {
                int costNou=it->second;
                int nodNou=it->first;

                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>>cost;
        g[x].push_back({y, cost});
    }
    fin.close();

    dijkstra(1);

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

    fout.close();

    return 0;
}