Cod sursa(job #2387310)

Utilizator Bulboaca_EugenBulboaca Alexandru Eugen Bulboaca_Eugen Data 24 martie 2019 14:59:41
Problema Algoritmul Bellman-Ford Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.21 kb
#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 5;
const int ABC = 1e9 + 9;
struct edge{
    int dest, cost;
};                      ///de revazut
std::vector <edge> G[MAXN];
std::queue <int> q;
int dist[MAXN] ;
void initializerG(){
    for(int i = 1; i <= MAXN; ++i) dist[i] = ABC;
}
void bellmanford(int start){
    q.push(start);
    dist[start] = 0;
    while(q.size()){
        int node = q.front();
        q.pop();
        if(dist[node] < -1*1000) break;
        for(auto x: G[node]){
            if(dist[x.dest] > dist[node] + x.cost){
                dist[x.dest] = dist[node] + x.cost;
                q.push(x.dest);
            }
        }
    }
}
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
int main()
{
    int n, m, start;
    fin >> n >> m >> start;
    for(int i = 1; i <= m; ++i){
        int x, y, c;
        fin >> x >> y >> c;
        G[x].push_back({y, c});
    }
    initializerG();
    bellmanford(1);
    for(int i = 2; i <= n; ++i){
        if(dist[i] < -1*1000) {
            fout << "Ciclu negativ";
            return 0;
        }
    }
    for(int i = 2; i <= n; ++i)
        fout << dist[i] <<  " ";
    return 0;
}