CSAcademy breadth_first_search

// aarifshuvo   ``CSEJU

#include <bits/stdc++.h>
#define ll long long
#define pb push_back
#define SZ(x) ((int)(x).size())
#define scl(x) scanf("%lld", &x)
#define scll(x,y) scanf("%lld %lld", &x, &y)
#define all(x) (x).begin(),(x).end()
#define mem(a,d) memset(a,d,sizeof a)
#define REP(i,n) for(int i=0;i<n;i++)
#define REV(i,n) for(int i=n-1;i>=0;i--)
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define pri(a) cout<<a<<endl
#define prii(a,b) cout<<a<<" "<<b<<endl
using namespace std;

#define inf 123456789

vector<int> adj[1000007];
int dis[1000007];
int vis[1000007];

void bfs(int st)
{
    queue<int> bfsq;

    bfsq.push(st);
    dis[st] = 0;
    vis[st] = 1;

    while(SZ(bfsq))
    {
        int u = bfsq.front();
        bfsq.pop();

        REP(i,SZ(adj[u]))
        {
            int v = adj[u][i];

            if(vis[v]==0)
            {
                vis[v] = 1;
                dis[v] = dis[u] + 1;
                bfsq.push(v) ;
            }
        }
    }
}

int main()
{
    int u,v,n,e,st;
    cin>>n>>e>>st;

    FOR(i,1,e)
    {
        cin>>u>>v;
        adj[u].pb(v);
    }

    FOR(i,1,n) dis[i] = inf;

    bfs(st);

    FOR(i,1,n)
    {
        if(dis[i]==inf) printf("-1 ");
        else printf("%d ", dis[i]);
    }
    puts("");

    return 0;
}