Cod sursa(job #2525673)

Utilizator vlad082002Ciocoiu Vlad vlad082002 Data 17 ianuarie 2020 17:41:14
Problema Algoritmul Bellman-Ford Scor 65
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.4 kb
#include <bits/stdc++.h>
using namespace std;

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

vector< pair< int, int> > g[50005];
int dist[50005];
int n, m;
bool ciclu;


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



void solve() {
    for(int i = 2; i <= n; i++) dist[i] = 100000000;
    queue<int> q;
    bool inQueue[50005];
    int cnt[500005];
    for(int i = 1; i <= n; i++) cnt[i] = 1;
    for(int i = 1; i <= n; i++) {
        q.push(i);
        inQueue[i] = true;
    }

    while(!q.empty()) {
        int curr = q.front();

        if(cnt[curr] > n) {
            ciclu = true;
            return;
        }

        q.pop();
        inQueue[curr] = false;

        for(int i = 0; i < g[curr].size(); i++) {
            int next = g[curr][i].first, c = g[curr][i].second;

            if(dist[curr]+c < dist[next]) {
                dist[next] = dist[curr]+c;
                if(!inQueue[next]) {
                    q.push(next);
                    cnt[next]++;
                }
            }
        }
    }
}

void afis() {
    if(ciclu)
        fout << "Ciclu negativ!";
    else
        for(int i = 2; i <= n; i++)
            fout << dist[i] << ' ';
}

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