Cod sursa(job #1981983)

Utilizator MaligMamaliga cu smantana Malig Data 17 mai 2017 14:30:25
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.39 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");

#define ll long long
#define pb push_back
const int NMax = 5e4 + 5;
const int inf = 1e9 + 5;

int N,M;
int dist[NMax],nrInQueue[NMax];
bool inQueue[NMax];

struct elem {
    int y,c;
    elem(int _y = 0,int _c = 0) {
        y = _y;
        c = _c;
    }
};
vector<elem> v[NMax];

int main() {
    in>>N>>M;

    while (M--) {
        int x,y,c;
        in>>x>>y>>c;
        v[x].pb(elem(y,c));
    }

    for (int i=2;i <= N;++i) {
        dist[i] = inf;
    }
    dist[1] = 0;

    queue<int> Q;
    Q.push(1);
    while (Q.size()) {
        int node = Q.front();
        Q.pop();

        inQueue[node] = false;
        ++nrInQueue[node];
        if (nrInQueue[node] == N) {
            out<<"Ciclu negativ!\n";
            return 0;
        }

        for (auto e : v[node]) {
            int nxt = e.y, cost = e.c;
            if (dist[nxt] > dist[node] + cost) {
                dist[nxt] = dist[node] + cost;

                if (!inQueue[nxt]) {
                    inQueue[nxt] = true;
                    Q.push(nxt);
                }
            }
        }
    }

    for (int i=2;i <= N;++i) {
        out<<dist[i]<<' ';
    }

    in.close();out.close();
    return 0;
}