题解 | #【模板】单源最短路Ⅰ ‖ 无权图#

import java.io.*;
import java.util.*;
import java.math.BigInteger;

public class Main {
    static void solve() {
        int n = in.nextInt(), m = in.nextInt(), s = in.nextInt();
        List<List<Integer>> g = new ArrayList<>();
        for(int i=0;i<=n;i++) {
            g.add(new ArrayList<>());
        }
        for(int i=0;i<m;i++) {
            int u = in.nextInt(), v = in.nextInt();
            g.get(u).add(v);
        }
        Queue<Integer> q = new LinkedList<>();
         q.add(s);

        boolean[] vis = new boolean[n+1];
        int[] dis = new int[n+1];
        vis[s] =  true;
        Arrays.fill(dis,-1);
        dis[s] = 0;

        while(!q.isEmpty()) {
            int i = q.poll();
            for(int j : g.get(i)) {
                if(vis[j]) continue;
                q.add(j);
                vis[j] = true;
                dis[j] = dis[i] + 1;
            }
        }
        for(int i=1;i<=n;i++) {
            out.print(dis[i]+" ");
        }
    }

    public static void main(String[] args) {
        solve();
        out.flush();
    }

    static FastReader in = new FastReader();
    static PrintWriter out = new PrintWriter(System.out);

    static class FastReader {
        static BufferedReader br;
        static StringTokenizer st;

        FastReader() {
            br = new BufferedReader(new InputStreamReader(System.in));
        }

        String next() {
            String str = "";
            while (st == null || !st.hasMoreElements()) {
                try {
                    str = br.readLine();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
                st = new StringTokenizer(str);
            }
            return st.nextToken();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }
    }
}