Cod sursa(job #2972559)

Utilizator T1raduTaerel Radu Nicolae T1radu Data 29 ianuarie 2023 18:29:04
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.17 kb
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
const long long inf=10000000000;
int n,p,m,ciclu[50001];
vector<pair<int,int>> G[50001];
long long dist[50001];
queue<int> q;
int bf(int x)
{
    q.push(x);
    dist[x]=0;
    while(!q.empty())
    {
        int xc=q.front();
        ciclu[xc]++;
        if(ciclu[xc]>n)
            return -1;
        for(vector<pair<int,int>>::iterator it=G[xc].begin();it!=G[xc].end();++it)
        {
            if((*it).second+dist[xc]<dist[(*it).first])
            {
               dist[(*it).first]=(*it).second+dist[xc];
               q.push((*it).first);
            }
        }
        q.pop();
    }
    return 1;
}
int main()
{
    fin >> n >> m;
    for(int i=1;i<=m;i++)
    {
        int a,b,c;
        fin >> a >> b >> c;
        G[a].push_back(make_pair(b,c));
    }
    for(int i=1;i<=n;i++)
        dist[i]=inf;
    if(bf(1)==1)
    {
        for(int i=2;i<=n;i++)
        {
            fout << dist[i] << " ";
        }
    }
    else fout << "Ciclu negativ!";
    return 0;
}