Cod sursa(job #3156044)

Utilizator lolismekAlex Jerpelea lolismek Data 10 octombrie 2023 14:27:52
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.39 kb
#include <algorithm>
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

#define pii pair <int, int>

string filename = "bellmanford";

#ifdef LOCAL
    ifstream fin("input.in");
    ofstream fout("output.out");
#else
    ifstream fin(filename + ".in");
    ofstream fout(filename + ".out");
#endif

const int NMAX = 5e4;
const int INF = 1e9;

vector <pii> adj[NMAX + 1];

int dist[NMAX + 1];
int f[NMAX + 1];
bool inQ[NMAX + 1];

int main(){

    int n, m;
    fin >> n >> m;

    for(int i = 1; i <= m; i++){
        int a, b, c;
        fin >> a >> b >> c;
        adj[a].push_back({b, c});
    }

    queue <int> Q;
    Q.push(1);
    for(int i = 2; i <= n; i++){
        dist[i] = INF;
    }

    inQ[1] = true;

    while(!Q.empty()){
        int node = Q.front();
        Q.pop();
        inQ[node] = false;

        if(++f[node] > n){
            fout << "Ciclu negativ!\n";
            return 0;
        }

        for(pii vec : adj[node]){
            if(vec.second + dist[node] < dist[vec.first]){
                dist[vec.first] = vec.second + dist[node];
                if(!inQ[vec.first]){
                    Q.push(vec.first);
                }
            }
        }
    }

    for(int i = 2; i <= n; i++){
        fout << dist[i] << ' ';
    }
    fout << '\n';

    return 0;
}