Cod sursa(job #2495409)

Utilizator stefantagaTaga Stefan stefantaga Data 19 noiembrie 2019 12:43:13
Problema Algoritmul lui Dijkstra Scor 40
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.47 kb
#include <bits/stdc++.h>

using namespace std;
ifstream f("dijkstra.in");
ofstream g("dijkstra.out");
priority_queue <pair <int,int> ,vector <pair <int,int > > , greater <pair <int,int > > > h;
vector <pair <int,int > > v[50005];
int n,m,x,y,cost,mini[50005],nod,nod2,i,nr,sel[50005];
int main()
{
    f>>n>>m;
    for (i=1;i<=m;i++)
    {
        f>>x>>y>>cost;
        v[x].push_back({y,cost});
    }
    for (i=1;i<=n;i++)
    {
        mini[i]=-1;
    }
    mini[1]=0;
    for (i=0;i<v[1].size();i++)
    {
        nod=v[1][i].first;
        mini[nod]=v[1][i].second;
        h.push({mini[nod],nod});
    }
    nr=v[1].size()-1;
    while (nr)
    {
        while (!h.empty()&&sel[h.top().second]==1)
        {
            h.pop();
        }
        nr--;
        nod=h.top().second;
        sel[nod]=1;
        h.pop();
        for (i=0;i<v[nod].size();i++)
        {
            nod2=v[nod][i].first;
            if (mini[nod2]==-1)
            {
                nr++;
                mini[nod2]=mini[nod]+v[nod][i].second;
                h.push({mini[nod2],nod2});
            }
            else
            if (mini[nod]+v[nod][i].second<mini[nod2])
            {
                mini[nod2]=mini[nod]+v[nod][i].second;
                h.push({mini[nod2],nod2});
            }
        }
    }
    for (i=2;i<=n;i++)
    {
        if (mini[i]==-1)
        {
            mini[i]=0;
        }
        g<<mini[i]<<" ";
    }
    return 0;
}