Cod sursa(job #2717923)

Utilizator LeCapataIustinian Serban LeCapata Data 8 martie 2021 10:44:10
Problema Algoritmul lui Dijkstra Scor 20
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.47 kb
#include <fstream>
#include <vector>
#include <queue>
#define N 50005
#define INF 100000
using namespace std;

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

int cost[N];

struct dijkstra{
    int nod, cost;
};

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

int n, m;
bool viz[N];
vector<dijkstra> graf[N];
priority_queue<int, vector<int>, comp> coada;


void getDijkstra(int nodStart){
    for(int i = 1; i <= n; ++i)
        cost[i] = INF;

    cost[nodStart] = 0;
    coada.push(nodStart);
    viz[nodStart] = 1;

    while(!coada.empty()){
        int nod = coada.top();
        coada.pop();
        viz[nod] = 0;

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

            if(cost[nod] + costVecin < cost[vecin])
                cost[vecin] = cost[nod] + costVecin;

            if(viz[vecin] == 0){
                coada.push(vecin);
                viz[vecin] = 1;
            }
        }
    }
}


int main()
{
    in>>n>>m;
    for(int i = 1; i <= m; ++i){
        int x, y;
        dijkstra nd;
        in>>x>>y>>nd.cost;

        nd.nod = y;
        graf[x].push_back(nd);
    }

    getDijkstra(1);

    for(int i = 2; i <= n; ++i)
        if(cost[i] != INF) out<<cost[i]<<" ";
        else out<<0<<" ";
    in.close();
    out.close();
    return 0;
}