Cod sursa(job #1992595)

Utilizator patcasrarespatcas rares danut patcasrares Data 20 iunie 2017 21:54:40
Problema Algoritmul lui Dijkstra Scor 90
Compilator cpp Status done
Runda Arhiva educationala Marime 1.63 kb
#include<fstream>
#include<queue>
#include<algorithm>
#include<vector>
#include<set>
#define DN 50005
using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
int n,m,a,b,c;
long long M;
long long dist[DN],expe[DN];
vector<pair<long long,int > >gr[DN];
typedef pair<long long,int >pii;
struct cmp
{
    bool operator()(pii A,pii B)
    {
        return A.first<B.first;
    }
};
multiset<pair<long long,int>,cmp >s;

void ve()
{
    int i;
    long long mi=M,ne;
    for(i=2;i<=n;i++)
    {
        dist[i]=M;
        s.insert(make_pair(M,i));
    }
    dist[1]=0;
    s.insert(make_pair(0,1));
    while(!s.empty())
    {
        set< pair<long long,int> >::iterator it;
        it=s.begin();
        ne=it->second;
        mi=it->first;
        expe[ne]=1;
        s.erase(s.begin());
        if(mi!=M)
            for(i=0;i<gr[ne].size();i++)
            {
                int vecin=gr[ne][i].first;
                int cost=gr[ne][i].second;
                if(dist[ne]+cost<dist[vecin])
                {
                    if(dist[vecin]==M)
                        s.erase(make_pair(dist[vecin],vecin));
                    dist[vecin]=dist[ne]+cost;
                    if(expe[vecin]==0)
                        s.insert(make_pair(dist[vecin],vecin));
                }
            }

    }
}
int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>a>>b>>c;
        gr[a].push_back(make_pair(b,c));
    }
    M=20000*250000;
    ve();
    for(int i=2;i<=n;i++)
        if(dist[i]!=M)
            fout<<dist[i]<<' ';
        else fout<<0<<' ';
}