Cod sursa(job #3367029)

Utilizator AlexandruCorneaCornea Alexandru Mihai AlexandruCornea Data 5 octombrie 2026 19:00:47
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.43 kb
#include <bits/stdc++.h>
using namespace std;

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

const int NMAX=50005;
const long long INF=4e18;

int n,m;
vector<pair<int,int>> v[NMAX];

long long d[NMAX];
int cnt[NMAX];
bool inq[NMAX];
bool negativ;

void citire()
{
    fin>>n>>m;

    for(int i=1; i<=m; i++)
    {
        int x,y,c;
        fin>>x>>y>>c;

        v[x].push_back({y,c});
    }
}

void bellmanford()
{
    for(int i=1; i<=n; i++)
        d[i]=INF;

    queue<int> q;

    d[1]=0;
    q.push(1);
    inq[1]=1;

    while(!q.empty())
    {
        int nod=q.front();
        q.pop();

        inq[nod]=0;

        for(auto x:v[nod])
        {
            int vec=x.first;
            int cost=x.second;

            if(d[vec]>d[nod]+cost)
            {
                d[vec]=d[nod]+cost;
                cnt[vec]++;

                if(cnt[vec]>=n)
                {
                    negativ=true;
                    return;
                }

                if(!inq[vec])
                {
                    q.push(vec);
                    inq[vec]=1;
                }
            }
        }
    }
}

void afisare()
{
    if(negativ)
    {
        fout<<"Ciclu negativ!";
        return;
    }

    for(int i=2; i<=n; i++)
        fout<<d[i]<<" ";
}

int main()
{
    citire();
    bellmanford();
    afisare();

    return 0;
}