Cod sursa(job #1888241)

Utilizator leraValeria lera Data 21 februarie 2017 23:26:06
Problema Algoritmul lui Dijkstra Scor 30
Compilator cpp Status done
Runda Arhiva educationala Marime 1.35 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#define inf 999999999
#define Nmax 50005
#include <functional>
using namespace std;
ifstream fin("dijkstra.in");
ofstream fout("dijkstra.out");
priority_queue<pair<long long,int>,vector<pair<long long,int> >,greater<pair<long long,int> > >q;
long long cst[Nmax],viz[Nmax],n,m,a,b,c;
pair<long long,int>p;
vector<pair<long long,int> >v[Nmax];
bool inq[Nmax];
void parc(long long cost,int nod)
{
    viz[nod]=1;
    for(int i=0;i<v[nod].size();i++)
    {
        if(cst[nod]+v[nod][i].first<cst[v[nod][i].second])
        {
            cst[v[nod][i].second]=cst[nod]+v[nod][i].first;
            if(!viz[v[nod][i].second] && !inq[v[nod][i].second])
            {
                inq[v[nod][i].second]=1;
                q.push(make_pair(cst[v[nod][i].second],v[nod][i].second));
            }
        }
    }
   inq[nod]=0;
}
int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>a>>b>>c;
        v[a].push_back(make_pair(c,b));
    }
    for(int i=1;i<=n;i++)cst[i]=inf;
    cst[1]=0;
    inq[1]=1;
    q.push(make_pair(0,1));//cost si nod
    while(!q.empty())
    {
        p=q.top();
        parc(p.first,p.second);
        q.pop();
    }
    for(int i=2;i<=n;i++)if(cst[i]!=inf)fout<<cst[i]<<" ";
    else fout<<0<<" ";
    return 0;
}