Cod sursa(job #1486593)

Utilizator alevasluialeHuhurez Marius alevasluiale Data 15 septembrie 2015 10:20:48
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.8 kb
#include <fstream>
#include <queue>
#include <vector>
using namespace std;
ifstream fin("bfs.in");
ofstream fout("bfs.out");
vector<int>H[100001];
queue<int>Q;
int v[100001];
inline void lee(int s)
{
    Q.push(s);
    while(Q.size()!=0)
    {
        int top=Q.front();
        for(vector<int>::iterator it=H[top].begin();it!=H[top].end();it++)
        {
            if(v[*it]==0&&*it!=s)
            {
                v[*it]=v[top]+1;
                Q.push(*it);
            }
        }
        Q.pop();
    }
}
int main()
{
    int n,m,s,i,a,b;
    fin>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
        fin>>a>>b;
        H[a].push_back(b);
    }
    lee(s);
    for(i=1;i<=n;i++)
    {
        if(v[i]==0) v[i]=-1;
        if(i==s) v[i]=0;
        fout<<v[i]<<" ";
    }
}