Cod sursa(job #1223935)

Utilizator TudorMTudor Moldovanu TudorM Data 29 august 2014 11:28:22
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.93 kb
#include<fstream>
#include<vector>
#include<cstring>
#include<queue>
using namespace std;
ifstream f("bfs.in");
ofstream g("bfs.out");
int n, m, s, cost[100001];
bool viz[100001];
vector <int> v[100001];
queue <int> c;
void citire()
{
    int i, x, y;
    f>>n>>m>>s;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        v[x].push_back(y);
    }
}
void bfs(int x)
{
    int i, u, p;
    memset(cost,-1,sizeof(cost));
    u=p=1;
    c.push(x);
    cost[x]=0;
    viz[x]=1;
    while(!c.empty())
    {
        p=c.front();
        for(i=0;i<v[p].size();i++)
        {
            u=v[p][i];
            if(!viz[u])
            {
                cost[u]=cost[p]+1;
                c.push(u);
                viz[u]=1;
            }
        }
        c.pop();
    }
}
int main()
{
    citire();
    bfs(s);
    int i;
    for(i=1;i<=n;i++)g<<cost[i]<<" ";
    f.close();
    g.close();
    return 0;
}