Cod sursa(job #1043207)

Utilizator SeekHunt1334Septimiu Bodica SeekHunt1334 Data 28 noiembrie 2013 09:24:13
Problema Algoritmul lui Dijkstra Scor 10
Compilator cpp Status done
Runda Arhiva educationala Marime 1.35 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <algorithm>
#include <vector>
using namespace std;

typedef vector<int> VEC;
typedef pair<int, int> PI;
typedef vector<vector<PI> > Graph;

#define INF ( 1 << 30 )
#define DIM 50005

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

void Read();

int n, m;
Graph G(DIM);
vector<int> D(DIM, INF); // distance
vector<bool> viz(DIM);
priority_queue<PI, vector<PI>, greater<PI> > Q;

int main()
{
    Read();

    D[1] = 0; Q.push(make_pair(1, 0));

    while ( !Q.empty() )
    {
        int cur = Q.top().first; Q.pop(); // current node
        viz[cur] = true;

        vector<PI>::iterator it;
        for (it = G[cur].begin(); it != G[cur].end(); ++it)
        {
            int _y = it->first; int _cost = it->second; // _y = node _cost = cost
            if ( !viz[_y] && D[_y] > D[cur] + _cost )
                D[_y] = D[cur] + _cost, Q.push(make_pair(_y, D[_y]));
        }
    }

    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;
}

void Read()
{
    fin >> n >> m;

    int x, y, c;
    for (int i = 0; i < m; ++i)
    {
        fin >> x >> y >> c;
        G[x].push_back(make_pair(y, c));
    }
}