Cod sursa(job #3130070)

Utilizator RalucaioneteRalucaIonete Ralucaionete Data 16 mai 2023 19:20:37
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.27 kb
#include<fstream>
#include<vector>
#include<queue>
using namespace std;

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

const int N=5e4;
const int INF=1 << 30;

struct succesor
{
    int vf;
    int c;
};

vector<succesor> ls[N+1];
queue<int> q;
int n, d[N+1], nr_in_q[N+1];
bool in_q[N+1];

bool bf_moore()
{
    for(int i=2; i<=n; i++)
        d[i]=INF;
    d[1]=0;
    q.push(1);
    in_q[1]=true;
    nr_in_q[1]++;
    while(!q.empty())
    {
        int x = q.front();
        q.pop();
        for(auto s: ls[x])
        {
            int y = s.vf;
            int c = s.c;
            if(d[x] + c < d[y])
            {
                d[y] = d[x] + c;
                nr_in_q[y]++;
                if(nr_in_q[y] == n)
                    return false;
                if(!in_q[y])
                    q.push(y);
            }
        }
    }
    return true;
}

int main()
{
    int m;
    cin >> n >> m;
    for(int i=0; i<m; i++)
    {
        int x, y, c;
        cin >> x >> y >> c;
        ls[x].push_back((succesor){y, c});
    }
    if(bf_moore())
    {
        for(int i=2; i<=n; i++)
            cout << d[i] << " ";
    }
    else
    {
        cout << "Ciclu negativ!";
    }
    return 0;

}