Cod sursa(job #1400699)

Utilizator Ionut228Ionut Calofir Ionut228 Data 25 martie 2015 13:23:44
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.27 kb
#include <fstream>
#include <algorithm>
#include <vector>
#include <queue>
#include <cstring>

using namespace std;

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

const int INF = 0x3f3f3f3f;

int N, M;
int D[50005];
vector<pair<int, int> > V[50005];
queue<pair<int, int> > Q;

void bellman()
{
    memset(D, INF, sizeof(D));
    D[1] = 0;
    Q.push(make_pair(1, 0));

    while (!Q.empty())
    {
        int now = Q.front().first;
        int nowc = Q.front().second;
        Q.pop();

        for (vector<pair<int, int> >::iterator it = V[now].begin(); it != V[now].end(); ++it)
        {
            if (nowc + it->second < D[it->first])
            {
                D[it->first] = nowc + it->second;
                Q.push(make_pair(it->first, nowc + it->second));
            }
        }
    }
}

int main()
{
    fin >> N >> M;
    for (int i = 1, nod1, nod2, cost; i <= M; ++i)
    {
        fin >> nod1 >> nod2 >> cost;
        V[nod1].push_back(make_pair(nod2, cost));
    }

    bellman();

    for (int i = 2; i <= N; ++i)
    {
        if (D[i] == INF)
            fout << 0 << ' ';
        else
            fout << D[i] << ' ';
    }
    fout << '\n';

    fin.close();
    fout.close();
    return 0;
}