Cod sursa(job #2369236)

Utilizator mihnea_toaderToader Mihnea mihnea_toader Data 5 martie 2019 21:53:09
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.51 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#include <limits.h>

#define AMAX 50010

using namespace std;

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

queue <int> q;

int d[AMAX], fr[AMAX], ap[AMAX], n, ok=0;;

struct Adiacenta {
    int vecin, cost;

};

vector <Adiacenta> graph[AMAX];

void bf (int nod)
{
    d[nod]=0;
    q.push(nod);
    fr[nod]++;
    ap[nod]=1;

    while (!q.empty())
    {
        nod=q.front();
        q.pop();
        ap[nod]=0;
        for (int i=0;i<graph[nod].size();i++)
        {
            if (d[nod]+graph[nod][i].cost<d[graph[nod][i].vecin])
            {
                d[graph[nod][i].vecin]=d[nod]+graph[nod][i].cost;
                if (ap[graph[nod][i].vecin]==0)
                {
                    q.push(graph[nod][i].vecin);
                    ap[graph[nod][i].vecin]=1;
                    fr[graph[nod][i].vecin]++;

                    if (fr[graph[nod][i].vecin]>n)
                    {
                        fout<<"Ciclu negativ!";
                        ok=1;
                        return;
                    }
                }
            }
        }
    }
}

int main()
{
    int m, x, y, c;
    fin>>n>>m;
    for(int i=0;i<m;i++)
    {
        fin>>x>>y>>c;
        graph[x].push_back({y,c});
    }
    for (int i=1;i<=n;i++)
        d[i]=INT_MAX;
    bf(1);
    if (!ok)
        for (int i=2;i<=n;i++)
            fout<<d[i]<<" ";
    return 0;
}