Cod sursa(job #2137230)

Utilizator MoleRatFuia Mihai MoleRat Data 20 februarie 2018 17:56:11
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.52 kb
#include <fstream>
#include <vector>
#include <set>
#include <algorithm>
using namespace std;
ifstream fin("bellmanford.in");
ofstream fout("bellmanford.out");
typedef struct muc
{
    long x, y, z;
} MU;
MU M[250010];
long C[50010];
bool F[50010];
vector <long> A[50010];
vector <pair<long, long> > H;
int main()
{
    int n,m;
    fin>>n>>m;
    for(int i=1; i<=m; i++)
    {
        fin>>M[i].x>>M[i].y>>M[i].z;
        A[M[i].x].push_back(i);
    }
    C[1]=0;
    for(int i=2; i<=n; i++)
        C[i]=2000000000;
    H.push_back(make_pair(0, 1));
    make_heap(H.begin(), H.end());
    pair<long, long> per;
    int i, j, nod, poz;
    long long pas=0;
    while(H.size() && pas<=1LL*n*m)
    {
        pas++;
        pop_heap(H.begin(), H.end());
        per=H.back();
        H.pop_back();
        nod=per.second;
        F[nod]=0;
        for(j=0; j<A[nod].size(); j++)
        {
            poz=A[nod][j];
            if(C[M[poz].x]+M[poz].z<C[M[poz].y])
            {
                C[M[poz].y]=C[M[poz].x]+M[poz].z;
                if(!F[M[poz].y])
                {
                    F[M[poz].y]=1;
                    H.push_back(make_pair(-C[M[poz].y], M[poz].y));
                    push_heap(H.begin(), H.end());
                }
            }
        }
    }
    for(int i=1; i<=m; i++)
        if(C[M[i].x]+M[i].z<C[M[i].y])
        {
            fout<<"Ciclu negativ!";
            return 0;
        }
    for(i=2; i<=n; i++)
        fout<<C[i]<<' ';
    return 0;
}