Cod sursa(job #2557231)

Utilizator dumitrustefaniaDumitru Stefania dumitrustefania Data 25 februarie 2020 17:35:30
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#include <bits/stdc++.h>
#define nmax 50001
#define mmax 250001
#define pb push_back
using namespace std;
ifstream f("bellmanford.in");
ofstream g("bellmanford.out");
int viz[nmax],nod,cost,x,cerinta,max1,n,m,i,d[nmax],y,c;
vector <pair <int,int> >v[nmax];
int ciclu,fr[nmax],nod2;
bool in_queue[nmax];
queue <int>q;

int main()
{
    f>>n>>m;
    for(i=1; i<=m; i++)
    {
        f>>x>>y>>c;
        v[x].pb({y,c});
    }
    ciclu=0;
    for(i=1; i<=n; i++)
        d[i]=1<<30;
    d[1]=0;
    fr[1]++;
    in_queue[1]=1;
    q.push(1);
    while(!q.empty()&&!ciclu)
    {
        nod=q.front();
        q.pop();
        in_queue[nod]=0;
        for(i=0; i<v[nod].size(); i++)
        {
            nod2=v[nod][i].first;
            cost=v[nod][i].second;
            if(d[nod2]>d[nod]+cost)
            {
                d[nod2]=d[nod]+cost;
                if(fr[nod2]>n)
                    ciclu=1;
                else
                {
                    q.push(nod2);
                    in_queue[nod2]=1;
                    fr[nod2]++;
                }
            }
        }

    }

    if(ciclu==0)
    {
        for(i=2; i<=n; i++)
            g<<d[i]<<" ";

    }
    else
        g<<"Ciclu negativ!";
    return 0;
}