Cod sursa(job #2566825)

Utilizator vlad082002Ciocoiu Vlad vlad082002 Data 3 martie 2020 13:05:49
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.34 kb
#include <fstream>
#include <queue>
#include <vector>
using namespace std;

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

const int inf = 1000000000;
int n, m, dist[100005];
int aparitii[100005];
bool inqueue[100005], cycle;
vector<pair<int, int> > g[100005];

void citire() {
    fin >> n >> m;
    int a, b, c;
    while(m--) {
        fin >> a >> b >> c;
        g[a].push_back({b, c});
    }
}

void solve() {
    queue<int> q;
    for(int i = 1; i <= n; i++)
        dist[i] = inf;
    dist[1] = 0;
    q.push(1);
    while(!q.empty() && !cycle) {
        int curr = q.front();
        q.pop();
        inqueue[curr] = false;

        for(int i = 0; i < g[curr].size(); i++) {
            int next = g[curr][i].first;
            if(dist[next] > dist[curr]+g[curr][i].second) {
                dist[next] = dist[curr]+g[curr][i].second;
                if(!inqueue[next]) {
                    q.push(next);
                    aparitii[next]++;
                    inqueue[next] = true;
                    if(aparitii[next] > n)
                        cycle = true;
                }
            }
        }
    }
    if(cycle) fout << "Ciclu negativ!";
    else for(int i = 2; i <= n; i++)
            fout << dist[i] << ' ';
}

int main() {
    citire();
    solve();
}