Cod sursa(job #1967244)

Utilizator MaligMamaliga cu smantana Malig Data 16 aprilie 2017 12:09:43
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.44 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

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

typedef long long ll;
#define pb push_back
const int NMax = 5e4 + 5;
const int inf = 2e9 + 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;
    for (int i=1;i<=M;++i) {
        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 nod = Q.front();
        Q.pop();

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

        for (int k=0;k < (int)v[nod].size();++k) {
            int next = v[nod][k].y, cost = v[nod][k].c;
            if (dist[next] < dist[nod] + cost) {
                continue;
            }
            dist[next] = dist[nod] + cost;

            if (inQueue[next]) {
                continue;
            }
            inQueue[next] = true;
            Q.push(next);
        }
    }
    for (int i=2;i<=N;++i) {
        out<<dist[i]<<' ';
    }

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