Cod sursa(job #592177)

Utilizator APOCALYPTODragos APOCALYPTO Data 26 mai 2011 21:42:56
Problema Algoritmul Bellman-Ford Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.48 kb
using namespace std;
#include<iostream>
#include<fstream>
#include<vector>
#include<queue>
ofstream fout("bellmanford.out");
#define nmax 50010
#define oo 0x3f3f3f3f
#define pb push_back
struct nod{
int lg,c;};
vector<nod> G[nmax];
queue<int> q;
int noap[nmax],isinq[nmax],dp[nmax];
int N,M;
void solve()
{
    int i;
    q.push(1);
    isinq[1]=1;
    noap[1]=1;
    dp[1]=0;
    for(i=2;i<=N;i++)
    {
        dp[i]=oo;
    }
    int u;
    vector<nod>::iterator it;
    int ok=1;
    while(!q.empty() && ok)
    {
        u=q.front();
        q.pop();
        isinq[u]=0;
        for(it=G[u].begin();it<G[u].end();it++)
        {
            if(dp[it->lg]>dp[u]+it->c)
            {
                dp[it->lg]=dp[u]+it->c;
                if(!isinq[it->lg])
                {
                    q.push(it->lg);
                    isinq[it->lg]=1;
                    noap[it->lg]++;
                    if(noap[it->lg]>N)
                       ok=0;
                }
            }
        }

    }
    if(ok==0)
    {
        fout<<"Ciclu negativ!\n";
    }
    else
    {
        for(i=2;i<=N;i++)
        {
            if(dp[i]==oo)
              fout<<0<<" ";
             else
              fout<<dp[i]<<" ";
        }
    }
    fout<<"\n";
}

void cit()
{
    ifstream fin("bellmanford.in");

    fin>>N>>M;
    int i,x,y,z;
    for(i=1;i<=M;i++)
    {
        fin>>x>>y>>z;
        G[x].pb((nod){y,z});

    }

    fin.close();

}

int main()
{
    cit();
    solve();
    fout.close();
    return 0;
}