Cod sursa(job #2053162)

Utilizator denismanaManaila Denis Daniel denismana Data 31 octombrie 2017 16:18:41
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp Status done
Runda Arhiva educationala Marime 1.11 kb
#include <fstream>
#include <vector>
using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");
const int oo=2000000000,nmax=50005;
vector <pair<int,int> > v[nmax];
int n,m,d[nmax],cycle;
void citire()
{
    in>>n>>m;
    int i,x,y,cost;
    for(i=1;i<=m;i++)
    {
        in>>x>>y>>cost;
        v[x].push_back(make_pair(y,cost));
    }
}
void bellmanford()
{
    int i,k,j;
    for(i=2;i<=n;i++)
        d[i]=oo;
    for(k=1;k<=n;k++)
    {
        for(i=1;i<=n;i++)
        {
            for(j=0;j<v[i].size();j++)
            {
                int vecin=v[i][j].first;
                int cost=v[i][j].second;
                d[vecin]=min(d[vecin],d[i]+cost);
            }
        }
    }
    for(i=1;i<=n;i++)
    {
        for(j=0;j<v[i].size();j++)
        {
            int vecin=v[i][j].first,cost=v[i][j].second;
            if(d[vecin]>d[i]+cost)
            {
                cycle=1;
            }
        }
    }
}
int main()
{
    int i;
    citire();
    bellmanford();
    if(cycle==1)
        out<<"Ciclu negativ!";
    else
        for(i=2;i<=n;i++)
            out<<d[i]<<" ";
    return 0;
}