Cod sursa(job #956710)

Utilizator D4n13LMuntean Dan Iulian D4n13L Data 3 iunie 2013 19:15:55
Problema Algoritmul Bellman-Ford Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 1.35 kb
#include<fstream>
#include<queue>
#include<vector>
using namespace std;
ifstream in("bellmanford.in");
ofstream out("bellmanford.out");
bool s[50001];
struct graf{
    int x,cost;
};
vector<graf>a[10000];
queue<int>q;
int n,m,d[250001],nrq[250001];
bool bf(int);
void afisare();
int main()
{
    int i,p,y,cos;
    in>>n>>m;
    for(i=1;i<=m;i++)
    {
        in>>p>>y>>cos;
        graf w;
        w.x=y;
        w.cost=cos;
        a[p].push_back(w);
    }
    if(bf(1)==true)
        afisare();
    else
        out<<"Ciclu negativ!";
    return 0;
}
bool bf(int x0)
{
    int i,y,p,x;
    for(i=1;i<=n;i++)
        d[i]=100000;
    d[x0]=0;
    q.push(x0);
    s[x0]=true;
    nrq[x0]=1;
    while(!q.empty())
    {
        y=q.front();
        q.pop();
        for(i=0;i<a[y].size();i++)
        {

            if(d[y]+a[y][i].cost<d[a[y][i].x])
            {
                d[a[y][i].x]=a[y][i].cost+d[y];
                if(s[a[y][i].x]==false)
                   {
                     q.push(a[y][i].x);
                     s[a[y][i].x]=true;
                     nrq[a[y][i].x]++;
                   }


            }
            if(nrq[a[y][i].x]==n)
                return false;
        }

    }
    return true;
}

void afisare(){
    for(int i=2;i<=n;i++)
    {
        out<<d[i]<<" ";
    }
}