Cod sursa(job #1857153)

Utilizator kikiandreiCristian Andrei Popescu kikiandrei Data 25 ianuarie 2017 21:09:07
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.39 kb
#include <iostream>
#include <vector>
#include <fstream>
#include <queue>

using namespace std;

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

vector<pair<int, int>>g[50005];
int best[50005];
bool inq[50005];
int ap[50005];
queue <int> Q;

int main()
{
    int N,M,node;
    in>>N>>M;
    for (int i=1;i<=M;i++)
    {
        int a,b,c;
        in>>a>>b>>c;
        g[a].push_back(make_pair(b,c));
    }
    int S=1;
    best[S]=0;
    for (int i=2;i<=N;i++)
    {
        best[i]=50000001;
    }
    Q.push(S);
    ap[S]++;
    inq[S]=true;
    while(!Q.empty())
    {
        node=Q.front();
        Q.pop();
        inq[node]=false;
        for (int i=0;i<g[node].size();i++)
        {
            if(best[g[node][i].first]>best[node]+g[node][i].second)
            {
                best[g[node][i].first]=best[node]+g[node][i].second;
                if (inq[g[node][i].first]==false)
                {
                    inq[g[node][i].first]==true;
                    ap[g[node][i].first]++;
                    Q.push(g[node][i].first);
                    if (ap[g[node][i].first]>N)
                    {
                        out<<"Ciclu negativ!";
                        return 0;
                    }
                }
            }
        }
    }
    for (int i=2;i<=N;i++)
        out<<best[i]<<" ";

    return 0;
}