Cod sursa(job #505021)

Utilizator mraresMardare Rares mrares Data 29 noiembrie 2010 23:25:40
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.36 kb
#include <cstdio>
#include <fstream>
#include <queue>
#include <vector>
#define nmax 50010
#define inf 1000000

using namespace std;

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

//FILE *fin=fopen("dijkstra.in", "r");
//FILE *fout=fopen("dijkstra.out", "w");

int d[nmax]; //distantele
int uz[nmax]; //blocat 0 sau 1

int n, m, x, y, c;

vector< pair <int, int> > v[nmax];
vector< pair <int, int> >::iterator it, sf;

class cmp
{
    public:
    inline bool operator()(const int &x, const int &y) { return d[x]>d[y]; }
};

priority_queue< int, vector<int>, cmp > h; //heapul

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

    fill(d+2,d+n+1,inf);

    h.push(1);

    for(; !h.empty(); h.pop())
    {
        x = h.top();
        uz[x]=0;
        for(it=v[x].begin(), sf=v[x].end(); it<sf; ++it)
        {
            y=it->first;
            c=it->second;
            if(d[y]>d[x]+c)
            {
                d[y]=d[x]+c;
                if(!uz[y])
                {
                    h.push(y);
                    uz[y]=1;
                }
            }
        }
    }

    for(i=2; i<=n; ++i)
        if(d[i]!=inf)
            fout << d[i] << " ";
        else
            fout << 0 << " ";
}