Cod sursa(job #677688)

Utilizator laurionLaurentiu Ion laurion Data 10 februarie 2012 15:14:02
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.6 kb
//dijkstra cu priority queue
#include<cstdio>
#include<iostream>
#include<fstream>
#include<algorithm>
#include<set>
#include<queue>
#include<cstring>
#include<vector>
using namespace std;

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

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;
    vector<pair<int,int> > V;
    d[1]=0;
    V.push_back(make_pair(0,1));
    while(!V.empty()) {
        int nod=V[0].second,cost=V[0].first;
        pop_heap(V.begin(),V.end(),greater<pair<int,int> >());
        V.pop_back();
        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;
                V.push_back( make_pair( d[it->vec], it->vec ) );
                push_heap(V.begin(),V.end(),greater<pair<int,int> >());
            }
        }
    }

}
int main()
{
    int n,m;

    fin>>n>>m;

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

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

    return 0;
}