Cod sursa(job #2517964)

Utilizator cyg_Alex_codegicianBarbu Alexandru cyg_Alex_codegician Data 4 ianuarie 2020 16:22:48
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.43 kb
#include <fstream>
#include <vector>
#include <queue>
using namespace std;
const int nmax=50005,inf=1<<30;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
int n,m;
vector< pair<int,int>> muchii[nmax];
vector <int> v;
queue <int> coada;
int d[nmax];
int viz[nmax];
bool inCoada[nmax];
bool bellmanford(int s)
{
    for(int i=1;i<=n;i++)
    {
        viz[i]=0;
        inCoada[i]=false;
        d[i]=inf;
    }
    d[s]=0;
    coada.push(s);
    inCoada[s]=true;
    while(!coada.empty())
    {
        int nodCurent=coada.front();
        viz[nodCurent]++;
        if(viz[nodCurent]>=n)
            return false;
        coada.pop();
        inCoada[nodCurent]=false;
        for(int i=0;i<muchii[nodCurent].size();i++)
        {
            int vecin=muchii[nodCurent][i].first;
            int cost=muchii[nodCurent][i].second;
            if(d[nodCurent]+cost<d[vecin])
            {
                d[vecin]=d[nodCurent]+cost;
                if(!inCoada[vecin])
                {
                    inCoada[vecin]=true;
                    coada.push(vecin);
                }
            }
        }
    }
    return true;
}
int main()
{
    fin >> n >> m;
    for(int i=1;i<=m;i++)
    {
        int x,y,c;
        fin >> x >> y >> c;
        muchii[x].push_back(make_pair(y,c));
    }
    if(bellmanford(1))
    {
        for(int i=2;i<=n;i++)
        {
            fout << d[i] << " ";
        }
    }
    else fout<<"Ciclu negativ!";
}