Go: package main

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

type vertexId int

type vertex struct {
	id vertexId
	visitedAt int
	adjs []vertexId
}

func createVertex(id int, adjsInt []int) vertex {
	adjs := make([]vertexId, len(adjsInt))
	for i := 0; i < len(adjs); i++ {
		adjs[i] = vertexId(adjsInt[i])
	}
	return vertex{
		id: vertexId(id),
		visitedAt: -1,
		adjs: adjs,
	}
}

func (v *vertex) isVisited() bool {
	return v.visitedAt >= 0
}

func bfs(id vertexId, vqueue []vertexId, vertices []vertex) {
	vertex := &vertices[id-1]
	for _, vid := range vertex.adjs {
		if !vertices[vid-1].isVisited() {
			(&vertices[vid-1]).visitedAt = vertex.visitedAt+1
			vqueue = append(vqueue, vid)
		}
	}
	if len(vqueue) > 0 {
		nextId := vqueue[0]
		nextVqueue := vqueue[1:]
		bfs(nextId, nextVqueue, vertices)
	}
}

func solveBfs(vertices []vertex) {
	vertex := &vertices[0]
	vertex.visitedAt = 0
	vqueue := make([]vertexId, 0)
	bfs(vertex.id, vqueue, vertices)
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	n, err := nextInt(sc)
	if err != nil {
		panic(err)
	}

	vertices := make([]vertex, n)
	for i := 0; i < n; i++ {
		id, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjN, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		adjs := make([]int, adjN)
		for j := 0; j < adjN; j++ {
			adjId, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			adjs[j] = adjId
		}
		vertices[i] = createVertex(id, adjs)
	}

	solveBfs(vertices)

	for i := 0; i < n; i++ {
		fmt.Printf("%d %d\n", vertices[i].id, vertices[i].visitedAt)
	}
}

func nextText(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

func nextInt(sc *bufio.Scanner) (int, error) {
	return strconv.Atoi(nextText(sc))
}

Python: from collections import deque
n = int(input())
d = [-1]*n
d[0] = 0
M = []
for i in range(n):
    adj = list(map(int,input().split()))
    if adj[1] == 0:
        M += [[]]
    else:
        M += [adj[2:]]
Q = deque([0])

while Q != deque([]):
  u = Q.popleft()
  for i in range(len(M[u])):
    v = M[u][i]-1
    if d[v] == -1:
      d[v] = d[u] + 1
      Q.append(v)
for i in range(n):
  print(i+1,d[i])

Python: from __future__ import print_function
import time
from sys import stdin
from Queue import Queue
start = time.clock()
i = 0
num=int(stdin.readline())
L=[]
for _ in range(num):
    L.append([int(s) for s in stdin.readline().split()[2:]])
 
d=[-1]*num
d[0]=0
q=Queue(100)
q.put(0)
while not q.empty():
    u=q.get()
    for v in L[u]:
        if d[v-1]<0:
            d[v-1]=d[u]+1
            q.put(v-1)
for i,v in enumerate(d):
    print (i+1,v)

Python: n = int(raw_input())

d = [99999 for i in range(n)] 
G = [0 for i in range(n)] 
a = [[0 for i in range(n)] for j in range(n)]
 
for i in range(n):
    G = map(int, raw_input().split())
    for j in range(G[1]):
        a[G[0]-1][G[2+j]-1] = 1
  
def bfs_visit(s):
    for k in range(n):
      if a[s][k] == 1:
       if d[k] > d[s]+1:
         d[k] = d[s]+1
         bfs_visit(k)
d[0] = 0 
for s in range(n):
    bfs_visit(s)
for s in range(s):
    if d[s] == 99999:
       d[s] = -1
for s in range(n):
    print (s+1,d[s])

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 = tuple([] 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 collections import deque
from enum import Enum, auto

class Color(Enum):
    WHITE = auto()
    GRAY = auto()
    BLACK = auto()

n = int(input())
d = [0 for i in range(n)]
f = [0 for i in range(n)]

colors = [] # 頂点の訪問状態
A = [[0 for j in range(n)] for i in range(n)] # 隣接行列
queue = deque([])

# 隣接行列の初期化
for i in range(n):
    arr = list(map(int, input().split(' ')))
    u, k, v = arr[0], arr[1], arr[2:]
    for j in range(k):
        A[u-1][v[j]-1] = 1

def bfs_init():
    global colors
    colors = [Color.WHITE for i in range(n)]
    d[0] = 0
    bfs(0, 1)

def bfs(u, dist):
    global queue
    colors[u] = Color.GRAY

    for v in range(n):
        if A[u][v] == 1 and colors[v] == Color.WHITE:
            d[v] = dist
            queue.append(v)

    while len(queue) > 0:
        v = queue.pop()
        bfs(v, dist+1)

bfs_init()

for u in range(n):
    if colors[u] == Color.WHITE:
        d[u] = -1

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

Python: #coding:utf-8
n = int(input())
Q = [1]
M = [[False for i in range(n)] for j in range(n)]
dataList = []
for i in range(n):
    data = list(map(int,input().split()))
    dataList.append(data)
    for j in range(data[1]):
        v = data[j+2] - 1
        M[i][v] = True
color = ["white" for i in range(n)]
d = [-1 for i in range(n)]
d[0] = 0
while Q != []:
    u = Q.pop() - 1
    color[u] = "gray"
    data = dataList[u]
    for i in range(data[1]):
        v = data[i+2] - 1
        if M[u][v] == True and color[v] == "white":
            d[v] = d[u] + 1
            Q.append(v+1)
    color[u] = "black"

for i,j in enumerate(d,1):
    print(i,j)

Python: n = input()

G = [[0 for j in range(n)] for i in range(n)]

for i in range(n):
    G

Python: n = int(raw_input()) 

G = [0 for i in range(n)] 
a = [[0 for i in range(n)] for j in range(n)]
dis = [99999 for i in range(n)]

def bfs_visit(s):
    for k in range(n):
      if a[s][k] == 1:
        if dis[k] > dis[s] + 1:
          dis[k] = dis[s] + 1
          bfs_visit(k)

for i in range(n):
    G = map(int, raw_input().split())
    for j in range(G[1]):
        a[G[0]-1][G[2+j]-1] = 1
 
dis[0] = 0
for s in range(n):
    bfs_visit(s)
for s in range(n):
    if dis[s] == 99999:
       dis[s] = -1
for s in range(n):
    print (s+1, d[s])

Python: n = int(input())

m = [[] for _ in range(n+1)]

for _ in range(n):
	tmp = [int(x) for x in input().split()]
	u,k,l = tmp[0],tmp[1],tmp[2:]
	m[u] += tmp[2:]
		
dp = [float('inf') for _ in range(n+1)]
dp[1] = 0
queue = [1]

while queue:
	t = queue.pop(0)
	for x in m[t]:
		if dp[x] > dp[t] + 1:
			dp[x] = dp[t] + 1
			queue.append(x)
			
for i,x in enumerate(dp):
	if i == 0:
		pass
	else:
		if x == float('inf'):
			print(i, -1)
		else:
			print(i, x)

Python: #木ではない
#非連結成分
#処理済みの判定、辺の距離はすべて1なので一度到達すればよい
from collections import deque

n = int(input())
V = [[] for _ in range(n+1)]
for _ in range(n):
    inpt = list(map(int,input().split( )))
    if len(inpt)>2:
        V[inpt[0]] = inpt[2:]

lrg = 10000
D = [lrg]*(n+1)
End = [0]*(n+1)

D[1] = 0
Deq = deque()

time = 1
Q = [1]
Deq.append(1)

while len(Deq) > 0:
    v = Deq.popleft()
    for i in V[v]:
        D[i] = min(D[i],D[v]+1)
        if End[i] == 0:
            Deq.append(i)
        End[i] = 1


for i in range(1,n+1):
    if D[i]<lrg-1:
        print(i,D[i])
    else:
        print(i,-1)