Cod sursa(job #1845611)

Utilizator GoogalAbabei Daniel Googal Data 11 ianuarie 2017 18:29:53
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.52 kb
#include <fstream>
#include <vector>
#include <queue>
#define nmax 50001
#define INF 1<<30

using namespace std;

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

int n,m,cost[nmax],aparnod[nmax];
bool viz[nmax],ok=true;

vector < pair < int, int > > leg[nmax];

queue < int > coada;

inline void read()
{
    int i,a,b,c;
    fin>>n>>m;
    for(i=2; i<=n; i++)
        cost[i]=INF;
    for(i=1; i<=m; i++)
    {
        fin>>a>>b>>c;
        leg[a].push_back(make_pair(b,c));
    }
    fin.close();
}

void bellford()
{
    int i,a;
    coada.push(1);
    while(!coada.empty())
    {
        a=coada.front();
        coada.pop();
        if(viz[a]==false)
        {
            viz[a]=true;
            for(i=0; i<leg[a].size(); i++)
            {
                if(cost[leg[a][i].first]>cost[a]+leg[a][i].second)
                {
                    cost[leg[a][i].first]=cost[a]+leg[a][i].second;
                    viz[leg[a][i].first]=false;
                    coada.push(leg[a][i].first);
                    if(++aparnod[leg[a][i].first]==n)
                    {
                        fout<<"Ciclu negativ!";
                        ok=false;
                        return;
                    }
                }
            }
        }
    }
}

inline void write()
{
        for(int i=2; i<=n; i++)
            fout<<cost[i]<<' ';

    fout.close();
}

int main()
{
    read();
    bellford();
    if(ok==true)
         write();
    return 0;
}