Cod sursa(job #2888430)

Utilizator ProBatmanBalint Leonard ProBatman Data 11 aprilie 2022 01:47:30
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.67 kb
#include <bits/stdc++.h>

using namespace std;

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

const int CMAX = 5e4+15;
const int oo = INT_MAX;

int n , m , x , y , c;
int D[CMAX];
int viz[CMAX];
vector < pair < int , int > > graf[CMAX];
queue < int > Q;

void citire()
{
    fin >> n >> m;
    for(int i=1;i<=m;i++)
    {
        fin >> x >> y >> c;
        graf[x].push_back({y,c});
        //cout << x << " " << y << " " << c << '\n';
    }
    /*
    for(int i=1;i<=n;i++)
    {
        cout << i << ": ";
        for(int j=0;j<graf[i].size();j++)
        {
            cout << graf[i][j].first << ", " << graf[i][j].second << " |";
        }
        cout << '\n';
    }
    */
}

bool bellmanford(int start){
    for(int i=1;i<=n;i++){
        viz[i] = 0;
        D[i] = oo;
    }
    D[start] = 0;
    Q.push(start);
    while(!Q.empty())
    {
        int nod_curent = Q.front();
        Q.pop();
        viz[nod_curent]++;
        //cout << "nod: " << nod_curent << '\n';
        if(viz[nod_curent]>=n)
            return false;
        //cout << "vecini: ";
        for(int i=0;i<graf[nod_curent].size();i++)
        {
            int vecin = graf[nod_curent][i].first;
            int cost = graf[nod_curent][i].second;
            if(D[nod_curent]+cost<D[vecin]){
                D[vecin] = D[nod_curent] + cost;
                Q.push(vecin);
            }
        }
    }
    return true;
}

int main()
{
    citire();
    if(bellmanford(1)==false)
    {
        fout << "Ciclu negativ!";
    }
    else
    {
        for(int i=2;i<=n;i++)
            fout << D[i] << " ";
    }
    return 0;
}