Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

func main() {
	scn := bufio.NewScanner(os.Stdin)
	scn.Split(bufio.ScanWords)
	nextInt := func() int { scn.Scan(); r, _ := strconv.Atoi(scn.Text()); return r }
	w := bufio.NewWriter(os.Stdout)

	n := nextInt()
	vecs := make([][]int, n)
	for i := 0; i < n; i++ {
		u := nextInt()
		k := nextInt()
		for j := 0; j < k; j++ {
			vecs[u-1] = append(vecs[u-1], nextInt()-1)
		}
	}

	ds := make([]int, 0, n)
	for i := 0; i < n; i++ {
		ds = append(ds, -1)
	}

	q := make([]int, 0, n)
	q = append(q, 0)
	ds[0] = 0

	for len(q) > 0 {
		i := pop(&q)
		for _, v := range vecs[i] {
			if ds[v] == -1 {
				ds[v] = ds[i]+1
				q = append(q, v)
			}
		}
	}

	for i, d := range ds {
		fmt.Fprintln(w, i+1, d)
	}

	w.Flush()
}

func pop(q *[]int) int {
	v := (*q)[0]
	*q = (*q)[1:]
	return v
}

Python: from collections import deque

n = int(input())
m = [[0 for j in range(n)] for i in range(n)]
color = [0 for i in range(n)]
q = deque()
dist = [-1 for i in range(n)]


def bfs(s):
    color[s], dist[s] = 1, 0
    q.append(s)

    while len(q) != 0:
        u = q.popleft()
        for v in range(n):
            if m[u][v] == 1 and color[v] == 0:
                color[v], dist[v] = 1, dist[u] + 1
                q.append(v)

        color[u] = 2


def main():
    for i in range(n):
        data = list(map(int, input().split()))
        for j in range(2, len(data)):
            m[data[0]-1][data[j]-1] = 1

    for i in range(n):
        if color[i] == 0:
            bfs(i)

    for i in range(n):
        print(i+1, dist[i])


if __name__ == '__main__':
    main()

Python: import sys
input = sys.stdin.readline

from collections import deque

def getNeighbor(A, i):
    a = len(A)
    for k in range(2, a):
        M[i][A[k]-1] = 1

def bfs():
    u = q.popleft()
    c[u] = 1

    for v in range(n):
        if M[u][v] and c[v] == 0:
            q.append(v)
            d[v] = d[u] + 1
            c[v] = 1

    if q:
        bfs()

    return

    bfs()

q = deque([0])

n = int(input())
#color
c = [0] * n
d = [0] + [-1] * (n-1) #depth

M = [[0] * n for _ in range(n)]
t = 0

for i in range(n):
    A = list(map(int, input().split()))
    getNeighbor(A,i)

bfs()

for i in range(n):
    print(str(i+1), str(d[i]))

Python: def get_depth(graph,tmp_depth,vertex_list,depth_list):
    new_vertex_list=[]
    for vertex in vertex_list:
        for j in range(len(depth_list)):
            if(graph[vertex][j]!=0 and depth_list[j]==-1):
                depth_list[j]=tmp_depth + 1
                new_vertex_list.append(j)
    get_depth(graph,tmp_depth+1,new_vertex_list,depth_list)


#グラフの作成
n=int(input())
graph=[[0]*n for loop in range(n)]
for loop in range(n):
    tmp_ope=list(map(int,input().split()))
    for j in range(tmp_ope[1]):
        graph[tmp_ope[0]-1][tmp_ope[j+2]-1]=1


depth_list=[-1]*n
depth_list[0]=0
vertex_list=[0]
get_depth(graph,0,vertex_list,depth_list)

for i in range(n):
    print(f"{i+1} {depth_list[i]}")

Python: # -*- coding: utf-8 -*-
import sys
from collections import deque
sys.setrecursionlimit(10**9)
INF=10**18
MOD=10**9+7
input=lambda: sys.stdin.readline().rstrip()
YesNo=lambda b: print('Yes' if b else 'No')
YESNO=lambda b: print('YES' if b else 'NO')

def main():
    N=int(input())
    edge=[[] for _ in range(N)]
    for i in range(N):
        l=list(map(lambda x:int(x)-1,input().split()))
        edge[i]=l[2:]
    d=[INF]*N
    d[0]=0
    que=deque()
    que.append(0)
    while que:
        v=que.popleft()
        for nv in edge[v]:
            if d[nv]>d[v]+1:
                d[nv]=d[v]+1
                que.append(nv)
    for i in range(N):
        print(i+1,d[i] if d[i]!=INF else -1)

if __name__ == '__main__':
    main()

Python: def bfs(adj, s):
    n = len(adj)
    d = [-1 for _ in range(n)]
    c = [0 for _ in range(n)]

    d[s] = 0
    c[s] = 1

    queue = [s]

    while len(queue) > 0:
        u = queue.pop()
        for v in adj[u]:
            if c[v] == 0:
                c[v] = 1
                d[v] = d[u] + 1
                queue.append(v)

    return d


n = int(input())
adj = [[] for _ in range(n)]
for _ in range(n):
    s = [int(x) for x in input().split()]
    u = s[0]
    for v in s[2:]:
        adj[u - 1].append(v - 1)

d = bfs(adj, 0)

for i in range(n):
    print(str(i + 1) + " " + str(d[i]))

Python: N= int(input())
E = [input().split()[2:] for _ in range(N)]
Q = [0]
L = [0] + [-1]*N
frag = [1] + [0]*N
def func(ide):
    global Q
    for i in E[ide]:
        i = int(i) - 1
        if frag[i] != 1:frag[i] = 1;L[i] = L[ide] +1 ;Q.append(i)
        
    

while Q:top = Q[0];func(top);del Q[0]

for i in range(N):print(i + 1 ,int(L[i]))

Python: #!/usr/bin/env python
# -*- coding: utf-8 -*-

"""
input:
4
1 2 2 4
2 1 4
3 0
4 1 3

output:
1 0
2 1
3 2
4 1
"""

import sys
from collections import deque

UNVISITED, VISITED_IN_QUEUE, POPPED_OUT = 0, 1, 2


def generate_adj_matrix(v_info):
    for v_detail in v_info:
        v_index, adj_num, *adj_list = map(int, v_detail)
        # assert len(adj_list) == adj_num
        init_adj_table[v_index].extend(adj_list)
    return init_adj_table


def graph_bfs(v_init):
    status[v_init] = VISITED_IN_QUEUE
    distance[v_init] = 0
    queue.appendleft(v_init)

    while queue:
        current = queue.popleft()
        for v in adj_table[current]:
            if status[v] is UNVISITED:
                status[v] = VISITED_IN_QUEUE
                distance[v] = distance[current] + 1
                queue.append(v)
        status[current] = POPPED_OUT
    return distance


if __name__ == '__main__':
    _input = sys.stdin.readlines()
    vertices_num = int(_input[0])
    vertices_info = list(map(lambda x: x.split(), _input[1:]))
    init_adj_table = [[] for _ in range(vertices_num + 1)]
    # assert len(vertex_info) == vertex_num

    # config length = (vertex_num + 1)
    queue = deque()
    status = [UNVISITED] * (vertices_num + 1)
    distance = [-1] * (vertices_num + 1)

    adj_table = generate_adj_matrix(vertices_info)
    ans = graph_bfs(1)
    for k, v in enumerate(ans[1:], 1):
        print(k, v)

Python: from sys import stdin
from collections import deque

def read_graph(n):
    A = [ [0]*(n+1) for _ in range(n+1) ]
    for _ in range(n):
        line = deque(stdin.readline().strip().split())
        i = line.popleft()
        line.popleft()
        for k in line:
            A[int(i)][int(k)] = 1
    return A

def bfs_ctrl(n, A):
    color = ["WHITE"] * (n+1)
    d = [-1] * (n+1)
    Q = deque([])

    def bfs(s):
        nonlocal color
        nonlocal d
        nonlocal Q
        color[s] = "GRAY"
        d[s] = 0
        Q.append(s)

        while Q:
            u = Q.popleft()
            for v in range(1, n+1):
                if A[u][v] and color[v] == "WHITE":
                    color[v] = "GRAY"
                    d[v] = d[u] + 1
                    Q.append(v)

            color[u] = "BLACK"

    bfs(1)
    for i in range(1, n+1):
            print(i, d[i])

n = int(input())
A = read_graph(n)
bfs_ctrl(n, A)

Python: from collections import deque
INF = 1145141919810364364334
s = [None]
r = [None]

n = int(input())
for _ in range(n):
    temp = list(map(int,input().split()))
    s.append(temp[2:])
    
d = [INF] * (n+1)

d[1] = 0
q = deque()
q.append(1)

while q:
    x = q.popleft()
    for i in s[x]:
        if d[i] == INF:
            q.append(i)
            
        d[i] = min(d[x] + 1 , d[i])
        
for i in range(1,n+1):
    if d[i] == INF:
        d[i] = -1
    print(i,d[i])