Cod sursa(job #2060924)

Utilizator vladcoroian2001Vlad Coroian vladcoroian2001 Data 8 noiembrie 2017 19:48:18
Problema BFS - Parcurgere in latime Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 0.88 kb
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream fi("bfs.in");
ofstream fo("bfs.out");
const int nmax=1e5;
queue <int> Q;
vector <int> V[nmax];
int SEEN[nmax],PATH[nmax],n,m,i,x,y,source;
int main()
{
    fi>>n>>m>>source;
    for(i=1;i<=m;i++)
    {
        fi>>x>>y;
        V[x].push_back(y);
    }
    Q.push(source);
    PATH[source]=0;
    while(!Q.empty())
    {
        x=Q.front();
        SEEN[x]=1;
        Q.pop();
        for(i=0;i<V[x].size();i++)
        {
            y=V[x][i];
            if(!SEEN[y])
            {
                Q.push(y);
                SEEN[y]=1;
                PATH[y]=PATH[x]+1;
            }
        }
    }
    for(i=1;i<=n;i++)
    {
        if(PATH[i]==0 && i!=source)
            PATH[i]=-1;
        fo<<PATH[i]<<" ";
    }
    fi.close();
    fo.close();
    return 0;
}