Cod sursa(job #2152558)

Utilizator DologXTurcas David Emil DologX Data 5 martie 2018 17:32:19
Problema Algoritmul Bellman-Ford Scor 20
Compilator cpp Status done
Runda Arhiva educationala Marime 1.08 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

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

int n,m,a,b,c,cost[50005],fr[50005],seen[50005];
bool ciclu;
vector < pair<int,int> > v[50005];
queue <int> q;
const int inf=(1<<30);

void BellmanFord(int x)
{
    int nod,nod1,cost1;
    cost[x]=0;
    q.push(x);
    while(!q.empty())
    {
        nod=q.front();
        seen[nod]++;
        if(seen[nod]>fr[nod]) {ciclu=1;break;}
        q.pop();
        for(int i=0;i<v[nod].size();i++)
        {
            nod1=v[nod][i].first;
            cost1=v[nod][i].second;
            if(cost[nod1]>cost[nod]+cost1) {cost[nod1]=cost[nod]+cost1;q.push(nod1);}
        }
    }
}

int main()
{
    fin>>n>>m;
    for(int i=1;i<=m;i++)
    {
        fin>>a>>b>>c;
        v[a].push_back(make_pair(b,c));
        fr[b]++;
    }
    for(int i=1;i<=n;i++) cost[i]=inf;
    BellmanFord(1);
    if(ciclu) fout<<"Ciclu negativ!";
        else for(int i=2;i<=n;i++) fout<<cost[i]<<' ';
    return 0;
}