Cod sursa(job #2418066)

Utilizator ALEx6430Alecs Andru ALEx6430 Data 3 mai 2019 13:54:52
Problema Algoritmul Bellman-Ford Scor 15
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.6 kb
#include <fstream>
#include <iostream>
#include <vector>
#define INF 1000000000
using namespace std;

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

int main()
{
    int n, m;
    in >> n >> m;

    struct edge
    {
        int x, y, c;
    };

    vector<edge> edges;

    for(int i = 0; i < m; i++)
    {
        int x, y, c;
        in >> x >> y >> c;

        edge e = {x,y,c};
        edges.push_back(e);
    }

    vector<int> d(n+1,INF);
    d[1] = 0;

    bool stop = false;

    for(int i = 1; i < n && !stop; i++)
    {
        stop = true;

        vector<bool> r(n+1,false);
        int cnt = 0;

        for(size_t j = 0; j < edges.size(); j++)
        {
            int x = edges[j].x;
            int y = edges[j].y;
            int c = edges[j].c;

            if(d[x]+c < d[y])
            {
                d[y] = d[x]+c;

                r[y] = true;
                stop = false;
            }
        }

        if(i > 1)
            for(auto it = edges.begin(); it != edges.end();)
            {
                int x = it->x;

                if(!r[x]) it = edges.erase(it);
                else it++;
            }
    }

    for(int i = 1; i <= n; i++)
        for(size_t j = 0; j < edges.size(); j++)
        {
            int x = edges[j].x;
            int y = edges[j].y;
            int c = edges[j].c;

            if(d[x]+c < d[y])
            {
                out << "Ciclu negativ!";
                return 0;
            }
        }

    for(int i = 2; i <= n; i++) out << d[i] << ' ';

    return 0;
}