Cod sursa(job #1977566)

Utilizator MaligMamaliga cu smantana Malig Data 5 mai 2017 15:27:01
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp Status done
Runda Arhiva educationala Marime 1.24 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <cstring>

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

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

int N,M;
int 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;
    }

    bool update = false;
    for (int c=1;c <= N;++c) {
        update = false;
        for (int i=1;i <= N;++i) {
            for (auto el : v[i]) {
                int nxt = el.y, cost = el.c;
                if (dist[nxt] > dist[i] + cost) {
                    dist[nxt] = dist[i] + cost;
                    update = true;
                }
            }
        }
    }

    if (update) {
        out<<"Ciclu negativ!\n";
    }
    else {
        for (int i=2;i <= N;++i) {
            out<<( (dist[i] == inf) ? 0 : dist[i] )<<' ';
        }
    }

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