Cod sursa(job #1981198)

Utilizator tanasaradutanasaradu tanasaradu Data 15 mai 2017 08:15:08
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.86 kb
#include <bits/stdc++.h>
#define nmax 100001
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
int n,m,varf,d[nmax],viz[nmax];
vector<int>h[nmax];
queue<int>q;
void Citire()
{
    int x,i,y;
    fin>>n>>m>>varf;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        h[x].push_back(y);
    }
}
inline void BFS()
{
    int i,x;
    q.push(varf);
    d[varf]=0;
    viz[varf]=1;
    while(!q.empty())
    {
        x=q.front();
        q.pop();
        for(i=0;i<h[x].size();i++)
            if(!viz[h[x][i]])
        {
            viz[h[x][i]]=1;
            d[h[x][i]]=d[x]+1;
            q.push(h[x][i]);
        }
    }
    for(i=1;i<=n;i++)
        if(!d[i] && i!=varf)
            fout<<"-1 ";
    else fout<<d[i]<<" ";
}
int main()
{
    Citire();
    BFS();
    fin.close();
    fout.close();
    return 0;
}