Cod sursa(job #2350481)

Utilizator fremenFremen fremen Data 21 februarie 2019 14:04:34
Problema Algoritmul Bellman-Ford Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.19 kb
#include <fstream>
#include <cstring>
#include <algorithm>
#include <queue>
#include <vector>
#include <climits>
using namespace std;

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

const int MAXN = 50005;
int n, m;
vector<pair<int, int>> v[MAXN];
queue<int> q;
bool viz[MAXN];
int d[MAXN];


int main() {

    fin >> n >> m;
    for (int i = 1; i <= n; ++i) {
        int a, b, c;
        fin >> a >> b >> c;
        v[a].push_back(make_pair(b, c));
        d[i] = INT_MAX;
    }

    d[1] = 0;
    q.push(1);
    viz[1] = 1;
    while(!q.empty()) {
        int node = q.front();
        for (int i = 0; i < v[node].size(); ++i) {
            int k = v[node][i].first;
            if (viz[k] == 1 && d[i] + v[node][i].second - d[k] < 0) {
                fout << "Ciclu negativ!";
                return 0;
            }
            if (d[k] > d[node] + v[node][i].second) {
                d[k] = d[node] + v[node][i].second;
                viz[k] = 1;
                q.push(k);
            }
        }
        q.pop();
    }

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

    fout.close();
    return 0;
}