Cod sursa(job #2751710)

Utilizator Catalinu23Gavrila Catalin Catalinu23 Data 15 mai 2021 17:22:39
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.57 kb
#include <bits/stdc++.h>
#define NMAX 50005
#define INF 2000000000
using namespace std;

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

int n,m;
bool negativ;
struct muchie
{
    int nod, cost;
};
vector<muchie> v[NMAX];
queue<int> q;
int dist[NMAX];
bool viz[NMAX];
int ap[NMAX];

void Citire()
{
    fin>>n>>m;
    muchie aux;
    for(int i=1; i<=m; i++)
    {
        int x;
        fin>>x>>aux.nod>>aux.cost;
        v[x].push_back(aux);
    }
    for(int i=1; i<=n; i++)
        dist[i]=INF;
}

void BellmanFord()
{
    dist[1]=0;
    viz[1]=1;
    ap[1]=1;
    q.push(1);
    while(!q.empty() && !negativ)
    {
        int w=q.front();
        q.pop();
        viz[w]=0;
        int dim=v[w].size();
        for(int i=0; i<dim; i++)
        {
            int nod=v[w][i].nod, cost=v[w][i].cost;
            if(dist[nod]>dist[w]+cost)
            {
                dist[nod]=dist[w]+cost;
                if(!viz[nod])
                {
                    q.push(nod);
                    viz[nod]=1;
                    ap[nod]++;
                    if(ap[nod]>n)
                        negativ=1;
                }
            }
        }
    }
}

void Afisare()
{
    if(negativ)
    {
        fout<<"Ciclu negativ!";
    }
    else
    {
        for(int i=2; i<=n; i++)
        {
            if(dist[i]==INF)
                fout<<"0 ";
            else
                fout<<dist[i]<<" ";
        }
    }
}

int main()
{
    Citire();
    BellmanFord();
    Afisare();
    return 0;
}