Cod sursa(job #1731722)

Utilizator SolcanMihaiSolcan Mihai Andrei SolcanMihai Data 19 iulie 2016 18:12:10
Problema Algoritmul Bellman-Ford Scor 35
Compilator cpp Status done
Runda Arhiva educationala Marime 1.57 kb
#include <cstdio>
#include <vector>
#include <queue>

using namespace std;

int n, m;
vector<pair<int, int> > vecini[50500];
queue<pair<int, int> > Q;
int viz[50500];
int dist[50500];

const int inf = 1<<20;

void citire()
{
    int tmp1, tmp2, tmp3;

    scanf("%d %d", &n, &m);

    for(int i = 0; i < m; i++)
    {
        scanf("%d %d %d", &tmp1, &tmp2, &tmp3);
        tmp1--;
        tmp2--;

        vecini[tmp1].push_back(make_pair(tmp3, tmp2));
    }

    for(int i = 1; i < n; i++)
    {
        dist[i] = inf;
    }
}

bool bellman()
{
    Q.push(make_pair(0, 0));

    while(!Q.empty())
    {
        int x = Q.front().first;
        int y = Q.front().second;
        Q.pop();

        int l = vecini[y].size();

        for(int i = 0; i < l; i++)
        {
            if(dist[vecini[y][i].second] > dist[y] + vecini[y][i].first)
            {
                dist[vecini[y][i].second] = dist[y] + vecini[y][i].first;
                viz[vecini[y][i].second]++;
                Q.push(vecini[y][i]);
            }
        }

        for(int i = 0; i < n; i++)
        {
            if(viz[i] > n)
            {
                return false;
            }
        }
    }

    return true;
}

int main()
{
    freopen("bellmanford.in", "r", stdin);
    freopen("bellmanford.out", "w", stdout);

    citire();
    if(bellman() == false)
    {
        printf("Ciclu negativ!");
    }
    else
    {
        for(int i = 1; i < n; i++)
        {
            printf("%d ", dist[i]);
        }
    }

    return 0;
}