Cod sursa(job #1193768)

Utilizator dianaa21Diana Pislaru dianaa21 Data 1 iunie 2014 18:27:55
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.99 kb
#include <fstream>
#include <queue>
using namespace std;
ifstream is ("bfs.in");
ofstream os ("bfs.out");
vector <int> v[100001];
queue <int> Q;
int n, m, s, viz[100001], nr[100001];

void Read();
void Cross();
int main()
{
    Read();
    Cross();
    for(int i = 1; i <=n; ++i)
    {
        if(viz[i] == 0)
            os << nr[i]-1 << ' ';
        else
            os << nr[i] << ' ';
    }
    return 0;
}
void Read()
{
    int x, y;
    is >> n >> m >> s;
    for(int i = 1; i <= m; ++i)
    {
        is >> x >> y;
        if(x != y)
        v[x].push_back(y);
    }
    viz[s] = 1;
    Q.push(s);
}
void Cross()
{
    int nod;
    while(!Q.empty())
    {
        nod = Q.front();
        Q.pop();
        for(int i = 0; i < v[nod].size(); ++i)
        {
            if(!viz[v[nod][i]])
            {
                viz[v[nod][i]] = 1;
                Q.push(v[nod][i]);
                nr[v[nod][i]] = nr[nod] + 1;
            }
        }
    }
}