Cod sursa(job #1987709)

Utilizator Mihai_PredaPreda Mihai Dragos Mihai_Preda Data 31 mai 2017 20:35:01
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.31 kb
#include <iostream>
#include <fstream>
#include <vector>
#include <queue>

using namespace std;

const int nMax = 50005;
const int mMax = 250005;
const int INF = (1 << 30);

int n, m;
vector<pair<int, int> > vecini[nMax];
int dp[nMax];
int cnt[nMax];

void citire()
{
    ifstream in("bellmanford.in");
    in >> n >> m;
    int x, y, c;
    for(int i = 1; i <= m; ++i)
    {
        in >> x >> y >> c;
        vecini[x].push_back(make_pair(y, c));
    }
    in.close();
}

void rezolvare()
{
    ofstream out("bellmanford.out");
    queue<int> q;
    q.push(1);
    cnt[1]++;
    dp[1] = 0;
    for(int i = 2; i <= n; ++i)
        dp[i] = INF;
    int nod;
    while(q.empty() == false)
    {
        nod = q.front();
        q.pop();
        for(auto &v:vecini[nod])
        {
            if(dp[nod] + v.second < dp[v.first])
            {
                dp[v.first] = dp[nod] + v.second;
                cnt[v.first]++;
                if(cnt[v.first] == n)
                {
                    out << "Ciclu negativ!";
                    return;
                }
                q.push(v.first);
            }
        }
    }
    for(int i = 2; i <= n; ++i)
        out << dp[i] << " ";
    out.close();
}

int main()
{
    citire();
    rezolvare();
    return 0;
}