Cod sursa(job #999339)

Utilizator manutrutaEmanuel Truta manutruta Data 19 septembrie 2013 22:36:28
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.28 kb
# include <cstring>
# include <iostream>
# include <fstream>
# include <vector>
# include <set>
using namespace std;

# define INF 0x3f3f3f3f
# define MAXN 50010
typedef vector< pair<int, int> > :: iterator iter;

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

int n, m;
vector<pair<int, int> > G[MAXN];
int dist[MAXN];
set< pair<int, int> > coada;

void dijkstra()
{
    memset(dist, 0x3f, sizeof(dist));
    dist[1] = 0;
    coada.insert(make_pair(0, 1));

    while (!coada.empty()) {
        pair<int, int> nd = *coada.begin();
        coada.erase(coada.begin());

        for (iter it = G[nd.second].begin(); it != G[nd.second].end(); it++) {
            if (dist[it->first] > dist[nd.second] + it->second) {
                dist[it->first] = dist[nd.second] + it->second;
                coada.insert(make_pair(dist[it->first], it->first));
            }
        }
    }

    for (int i = 2; i <= n; i++) {
        if (dist[i] == INF) {
            g << 0 << ' ';
        } else {
            g << dist[i] << ' ';
        }
    }
}

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

    dijkstra();

    return 0;
}