Cod sursa(job #2722936)

Utilizator LeCapataIustinian Serban LeCapata Data 13 martie 2021 13:24:22
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.48 kb
#include <fstream>
#include <vector>
#include <queue>
#define N 50005
#define INF 1000000
using namespace std;

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

struct nodGraf{
    int x, cost;
};

int costNoduri[N];

struct comp{
    bool operator()(int a, int b){
        return costNoduri[a] > costNoduri[b];
    }
};

int n, m;
bool vizitat[N];
vector<vector<nodGraf> > graf(N);
priority_queue<int, vector<int>, comp> coada;


void dijkstra(int nodStart){

    for(int i = 1; i <= n; ++i)
        costNoduri[i] = INF;

    coada.push(nodStart);
    vizitat[nodStart] = 1;
    costNoduri[nodStart] = 0;

    while(!coada.empty()){
        int nod = coada.top();
        coada.pop();

        vizitat[nod] = 0;

        for(size_t i = 0; i < graf[nod].size(); ++i){
            int vecin = graf[nod][i].x;
            int cost = graf[nod][i].cost;

            if(costNoduri[nod] + cost < costNoduri[vecin]){
                costNoduri[vecin] = costNoduri[nod] + cost;
                if(vizitat[vecin] == 0) coada.push(vecin), vizitat[vecin] = 1;
            }
        }
    }
}

int main()
{
    in>>n>>m;

    for(int i = 1; i <= m; ++i){
        int y; nodGraf nod;
        in>>y>>nod.x>>nod.cost;

        graf[y].push_back(nod);
    }

    dijkstra(1);

    for(int i = 2; i<= n; ++i)
        if(costNoduri[i] != INF) out<<costNoduri[i]<<" ";
        else out<<"0 ";


    in.close();
    out.close();
    return 0;
}