Cod sursa(job #2374571)

Utilizator caesar2001Stoica Alexandru caesar2001 Data 7 martie 2019 19:25:57
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.47 kb
#include <iostream>
#include <fstream>
#include <algorithm>
#include <vector>
#include <utility>
#include <cmath>
#include <string>
#include <cstring>
#include <set>
#include <queue>
#include <map>
#include <stack>
#include <iomanip>
#define ll long long
#define lsb(x) (x & -x)

using namespace std;

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

const int INF = 1e9;

int main() {

    int n, m;
    in >> n >> m;
    vector<vector<pair<int, int>>> g(n + 1);
    for(int i = 1; i <= m; i ++) {
        int x, y, c;
        in >> x >> y >> c;
        g[x].push_back({y, c});
    }

    queue<int> q;
    vector<int> dist(n + 1, INF);
    vector<bool> inq(n + 1, 0);
    vector<int> cnt(n + 1, 0);
    dist[1] = 0;
    q.push(1);
    inq[1] = 1;

    while(q.size()) {
        auto node = q.front();
        q.pop();;
        inq[node] = 0;

        for(auto it : g[node]) {
            if(dist[it.first] > dist[node] + it.second) {
                dist[it.first] = dist[node] + it.second;
                if(!inq[it.first]) {
                    inq[it.first] = 1;
                    q.push(it.first);
                    cnt[it.first] ++;

                    if(cnt[it.first] > n) {
                        out << "Ciclu negativ!";
                        return 0;
                    }
                }
            }
        }
    }

    for(int i = 2; i <= n; i ++)
        out << dist[i] << " ";

    return 0;
}