Cod sursa(job #677669)

Utilizator laurionLaurentiu Ion laurion Data 10 februarie 2012 14:49:32
Problema Algoritmul lui Dijkstra Scor 80
Compilator cpp Status done
Runda Arhiva educationala Marime 1.42 kb
//dijkstra cu priority queue
#include<cstdio>
#include<iostream>
#include<algorithm>
#include<set>
#include<queue>
#include<cstring>
#include<vector>
using namespace std;

struct muchie
{
    int vec,cost;
};

vector <muchie> G[50000+10];
int viz[50000+10],d[50000+10];
bool cmp(const pair<int,int> &a, const pair<int,int> &b)
{
    if(a.first == b.first)
        return a.second<b.second;
    return a.first<b.first;
}
inline void dijkstra()
{
    memset(d,0x3f,sizeof(d));
    priority_queue < pair<int,int>, vector<pair<int,int> >, greater<pair<int,int> > > Q;

    d[1]=0;
    Q.push(make_pair(0,1));
    while(!Q.empty())
    {
        int nod=Q.top().second,cost=Q.top().first;
        Q.pop();
        for(vector<muchie>::iterator it=G[nod].begin(),stop=G[nod].end();it<stop;++it)
        {
            if( d[it->vec] > cost + it->cost )
            {
                d[it->vec] = cost + it->cost;
                Q.push( make_pair( d[it->vec], it->vec ) );
            }
        }
    }

}
int main()
{
    freopen("dijkstra.in","rt",stdin);
    freopen("dijkstra.out","wt",stdout);

    int n,m;

    cin>>n>>m;

    for(int i=1;i<=m;++i)
    {
        int from,to,cost;
        cin>>from>>to>>cost;
        G[from].push_back((muchie){to,cost});
    }
    dijkstra();

    for(int i=2;i<=n;++i)
        cout<<((d[i]==0x3f3f3f3f)?0:d[i])<<' ';
    putchar('\n');

    return 0;
}