Cod sursa(job #2693952)

Utilizator QubeeStefan Ste Qubee Data 7 ianuarie 2021 18:03:58
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.47 kb
#include <bits/stdc++.h>

using namespace std;

ifstream f("dijkstra.in");
ofstream g("dijkstra.out");

const int oo = (1<<30);
const int NMAX = 50005;
int n, m;
int D[NMAX];
bool vizitat[NMAX];
vector < pair < int, int > > G[NMAX];

struct compara{

    bool operator()(int x, int y){
        return D[x] > D[y];

    }

};

priority_queue < int, vector < int >, compara > q;

void Read(){

    f >> n >> m;

    int i, x, y, c;

    for(i = 1; i <= m; ++i){
        f >> x >> y >> c;
        G[x].push_back(make_pair(y,c));
    }
}

void Dijkstra(int startNod){

    int i;
    for(i = 1; i <= n; ++i)
        D[i] = oo;

    D[startNod] = 0;
    q.push(startNod);
    vizitat[startNod] = true;

    while(!q.empty()){

        int nod = q.top();
        q.pop();
        vizitat[nod] = false;

        for(size_t i = 0; i < G[nod].size(); ++i){

            int vecin = G[nod][i].first;
            int cost = G[nod][i].second;

            if(D[nod] + cost < D[vecin]){

                D[vecin] = D[nod] + cost;
                if(vizitat[vecin] == false){
                    q.push(vecin);
                    vizitat[vecin] = true;

                }
            }
        }
    }
}

void Write(){
    int i;

    for(i = 2; i <= n; ++i)
        if(D[i] != oo)
            g<< D[i] << " ";
        else
            g << "0 ";

}

int main(){

    Read();
    Dijkstra(1);
    Write();

    return 0;
}