Cod sursa(job #2205076)

Utilizator biaiftimeIftime Bianca biaiftime Data 17 mai 2018 21:17:19
Problema Algoritmul lui Dijkstra Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.29 kb
#include <fstream>
#include <vector>
#include <set>
#define Nmax 50002
#define inf 20000001
using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
vector<pair<int,int> >muchii_graf[Nmax];
int n,m;
void Read()
{
    fin>>n>>m;
    int i,x,y,z;
    for(i=1;i<=m;++i)
    {
        fin>>x>>y>>z;
        muchii_graf[x].push_back(make_pair(y,z));
    }
}
void Dijkstra(int s)
{
    int i,x,cost;
    set< pair<int,int> >S;
    set< pair<int,int> >::iterator it;
    vector<int>d(n+1);
    for(i=1;i<=n;++i)
       if(d[i]==0&&i!=s)
          d[i]=inf;
    for(auto nod:muchii_graf[s])
        d[nod.first]=nod.second;
    for(i=1;i<=n;++i)
        if(i!=s)S.insert(make_pair(d[i],i));
    while(!S.empty())
    {
        it=S.begin();
        x=it->second;
        cost=it->first;
        S.erase(it);
        for(auto nod:muchii_graf[x])
            if(cost+nod.second<d[nod.first])
        {
            it=S.find(make_pair(d[nod.first],nod.first));
            S.erase(it);
            d[nod.first]=nod.second+cost;
            S.insert(make_pair(d[nod.first],nod.first));
        }
    }
    for(i=2;i<=n;++i)
        if(d[i]==inf)fout<<"0 ";
        else fout<<d[i]<<" ";
}
int main()
{
    Read();
    Dijkstra(1);
    return 0;
}