Cod sursa(job #2291029)

Utilizator vic_d54Doroftei Victor vic_d54 Data 27 noiembrie 2018 12:57:55
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.42 kb
#include <iostream>
#include <fstream>
#include <queue>
#include <vector>
#include <cstring>
#define NMAX 50000
#define MMAX 250000
#define INF  250000000
using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");

struct edge
{
    int e,c;
};
vector <edge> a[NMAX+5];
queue  <int>  q;
long long int n,m,cost[NMAX+5],nr_ori[NMAX+5];
bool viz[NMAX+5];

bool BellmanFord()
{
    int fr,nod;
    unsigned int i;
    q.push(1);
    while(!q.empty())
    {
        fr=q.front();
        q.pop();
        viz[fr]=0;
        for(i=0;i<a[fr].size();i++)
        {
            nod=a[fr][i].e;
            if(cost[nod]>cost[fr]+a[fr][i].c)
            {
                cost[nod]=cost[fr]+a[fr][i].c;
                if(!viz[nod])
                {
                    q.push(nod);
                    viz[nod]=1;
                    if(++nr_ori[nod]>n)
                    {
                        out<<"Ciclu negativ!";
                        return false;
                    }
                }
            }
        }
    }
    return true;
}

int main()
{
    int i,x;
    edge e2;
    in>>n>>m;
    for(i=1;i<=m;i++)
    {
        in>>x>>e2.e>>e2.c;
        a[x].push_back(e2);
    }
    for(i=1;i<=n;i++)
        cost[i]=INF;
    cost[1]=0;
    viz[1]=1;
    if(BellmanFord())
        for(i=2;i<=n;i++)
            out<<cost[i]<<' ';
    return 0;
}