Cod sursa(job #1995157)

Utilizator MaligMamaliga cu smantana Malig Data 27 iunie 2017 08:48:18
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.73 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>

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

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

int N,M;
bool inQueue[NMax];
int nrInQueue[NMax],dist[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<elem> Q;
    Q.push(elem(1,0));
    inQueue[1] = true;
    while (Q.size()) {
        elem e = Q.front();
        Q.pop();

        int node = e.y;
        inQueue[node] = false;
        //out<<node<<'\n';

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

            dist[nxt] = dist[node] + cost;

            if (!inQueue[nxt]) {
                Q.push(elem(nxt,dist[nxt]));
                inQueue[nxt] = true;

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

        /*
        for (int i=1;i <= N;++i) {
            out<<dist[i]<<' ';
        }
        out<<"\n";
        //*/
    }

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

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