Cod sursa(job #645330)

Utilizator voicuraduVoicu Radu voicuradu Data 9 decembrie 2011 11:12:50
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 0.9 kb
#include<cstdio>
#include<vector>
#include<queue>
using namespace std;
const int N=100010;
int n,m,s,x,y,d[100010];
vector<int> a[N];
void read()
{
    int i;
    freopen("bfs.in","r",stdin);
    freopen("bfs.out","w",stdout);
    scanf("%d%d%d",&n,&m,&s);
    while(m--)
    {
        scanf("%d%d",&x,&y);
        a[x].push_back(y);
    }
    for(i=1;i<=n;i++)
        d[i]=-1;
}

void bfs()
{
    queue<int> q;
    q.push(s);
    d[s]=0;
    while(!q.empty())
    {
        x=q.front();
        q.pop();
        for(size_t i=0;i<a[x].size();i++)
        {
            y=a[x][i];
            if(d[y]==-1)
            {
                d[y]=1+d[x];
                q.push(y);
            }
        }
    }
}

void rez()
{
    bfs();
    int i;
    for(i=1;i<=n;i++)
        printf("%d ",d[i]);
    printf("\n");
}

int main()
{
    read();
    rez();
    return 0;
}