Go: package main

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

type AdjacentList struct {
	matrix [][]int
}

func NewEmptyAdjacentList(dim int) *AdjacentList {
	matrix := make([][]int, dim)
	for i := 0; i < dim; i++ {
		matrix[i] = make([]int, dim)
	}
	return &AdjacentList{matrix: matrix}
}

func (al *AdjacentList) set(node int, adjacent int) {
	al.matrix[node-1][adjacent-1] = 1
}

func (al *AdjacentList) findAdjacentsFor(node int) []int {
	adjacents := []int{}
	for i, v := range al.matrix[node-1] {
		if v == 1 {
			adjacents = append(adjacents, i+1)
		}
	}
	return adjacents
}

type DistanceList struct {
	list []int
}

func NewDistanceList(dim int) *DistanceList {
	list := make([]int, dim)
	for i := 0; i < dim; i++ {
		list[i] = -1
	}
	return &DistanceList{list: list}
}

func (dl *DistanceList) set(node int, distance int) {
	dl.list[node-1] = distance
}

func (dl *DistanceList) get(node int) int {
	return dl.list[node-1]
}

func (dl *DistanceList) isVisited(node int) bool {
	return dl.list[node-1] >= 0
}

type Position struct {
	node     int
	distance int
}

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

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

	al := NewEmptyAdjacentList(dim)

	for i := 1; i <= dim; i++ {
		node, err := nextInt(sc)
		if err != nil {
			panic(err)
		}

		adjacentNum, err := nextInt(sc)
		if err != nil {
			panic(err)
		}
		for j := 0; j < adjacentNum; j++ {
			adjacent, err := nextInt(sc)
			if err != nil {
				panic(err)
			}
			al.set(node, adjacent)
		}
	}

	dl := NewDistanceList(dim)

	bfs(al, dl)

	for i := 1; i <= dim; i++ {
		fmt.Printf("%d %d\n", i, dl.get(i))
	}
}

func bfs(al *AdjacentList, dl *DistanceList) {
	stack := []Position{Position{node: 1, distance: 0}}
	for len(stack) > 0 {
		currentPosition := stack[0]
		stack = stack[1:]
		if !dl.isVisited(currentPosition.node) {
			dl.set(currentPosition.node, currentPosition.distance)
		}
		for _, v := range al.findAdjacentsFor(currentPosition.node) {
			stack = append(stack, Position{node: v, distance: currentPosition.distance + 1})
		}
	}
}

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

Python: N= int(input());E = [input().split()[2:] for _ in range(N)]
frag, T, L,Q = [0]*N, [0]*N, [0]*N, [0]
a,frag[0] = 100, 1
def func(ide):
    for i in E[ide]:
        i = int(i) - 1
        if frag[i] != 1:frag[i] = 1;L[i] = L[ide] +1 ;Q.append(i) 
        else:return

while Q:top = Q[0];func(top);del Q[0]
for i in range(n):
    if L[i] == 0:
        L[i] == -1

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

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 = [1000 for i in range(n)]
dis[0] = 0

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 dis[k] > dis[s] + 1:
         dis[k] = dis[s] + 1
         bfs_visit(k)

for s in range(n):
    bfs_visit(s)
for s in range(n):
    if dis[s] == 1000:
       dis[s] = -1
for s in range(n):
    print (s+1,dis[s])

Python: from collections import deque
N = int(input())
#グラフ入力受取
G = [[] for _ in range(N)]
for _ in range(N):
    a = list(map(int, input().split()))
    for i in a[2:]:
        G[a[0]-1].append(i-1)

#頂点1をスタートとした探索
dist = [-1]*N
que = deque()
dist[0] = 0
que.append(0)
while len(que)!=0:
    v = que.popleft()
    for nv in G[v]:
        if dist[nv] == -1:
            dist[nv] = dist[v]+1
            que.append(nv)
        
for i in range(N):
    print(str(i+1) + ' ' + str(dist[i]))

Python: from collections import deque


INFINITY = 10 ** 10
WHITE = 0
GRAY = 1
BLACK = 2


def breadth_first_search(u_start = 0):
    color[u_start] = GRAY
    d[u_start] = 0
    que.append(u_start)

    while que:
        u = que.popleft()
        for v in range(n):
            if matrix[u][v] and color[v] == WHITE:
                color[v] = GRAY
                d[v] = d[u] + 1
                que.append(v)
        color[u] = BLACK


# INPUT
n = int(input())


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

for i in range(n):

    u, k, *V = map(int, input().split())

    for v in V:
        v -= 1
        matrix[i][v] = 1


color = [WHITE] * n
d = [INFINITY] * n
que = deque([])

# PROCESS
breadth_first_search()


# OUTPUT
for i in range(n):
    if d[i] == INFINITY:
        distance = -1
    else:
        distance = d[i]

    print(i + 1, distance)

Python: # https://onlinejudge.u-aizu.ac.jp/courses/lesson/1/ALDS1/11/ALDS1_11_C
# 実家のような安心感
# 与えられるノード番号についてはすべて0based indexに治す

from collections import deque

# データの入力
N = int(input())
DG = {}
for i in range(N):
    tmp = input().split()
    if int(tmp[1]) != 0:
        DG[i] = [int(x)-1 for x in tmp[2:]]
    else:
        DG[i] = []


result = {}
is_visited = {key: False for key in range(N)}
# bfs
# 初期queue
que = deque([(0, 0)])  # 必要なものはnodeidと原点からの距離
while que:
    nodeid, cost = que.popleft()  # 先入れ先出し
    result[nodeid] = cost
    is_visited[nodeid] = True  # この文は最初の1for目しか意味ないんだけどなんかうまい方法ないのか
    for nextnode in DG[nodeid]:
        if is_visited[nextnode]:
            pass
        else:  # 未訪問のものについては探索候補に入れる
            que.append((nextnode, cost + 1))
            is_visited[nextnode] = True  # 探索候補に入れた瞬間に訪問管理しないと重複を生じる場合がある

for i in range(N):
    if is_visited[i]:
        print(i + 1, result[i])
    else:
        print(i+1, -1)

Python: N= int(input())
E = [input().split()[2:] for _ in range(N)]
frag, T, L,Q = [0]*N, [0]*N, [0]*N, [0]
a,frag[0] = 100, 1
def func(ide):
    for i in E[ide]:
        i = int(i) - 1
        if frag[i] != 1:frag[i] = 1;L[i] = L[ide] +1 ;Q.append(i) 
        else:return

while Q:top = Q[0];func(top);del Q[0]
for i in range(n):
    if L[i] == 0:
        L[i] == -1

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

Python: from collections import deque

N = int(input())

nodes = [tuple(map(int, input().split(' '))) for _ in range(N)]

distances = [-1] * (N + 1)

queue = deque()
queue.append((1, 0))

while len(queue) > 0:
    node, distance = queue.popleft()
    if distances[node] != -1:
        continue
    distances[node] = distance

    neighbors = nodes[node - 1][2:]
    for neighbor in neighbors:
        queue.append((neighbor, distance + 1))

for node in range(1, N + 1):
    print(node, distances[node])

Python: #coding: utf-8
inf = 100000000
n = int(input())

List = [0] + [list(map(int,input().split())) for i in range(n)]
color = [0] + ["white" for  i in range(n)]
d = [inf for i in range(n+1)]

s = 1
Q = [s]
d[s] = 0
while Q != []:
    q = Q.pop()
    if color[q] == "white":
        k = List[q][1]
        if k != 0:
            Q += List[q][2:2+k]
            for i in List[q][2:2+k]:
                d[i] = min(d[q] + 1, d[i])
    
    color[q] = "black"


for i, dis in enumerate(d[1:], 1):
    if dis == inf:
        dis = -1
    print(i, dis)

Python: # coding: utf-8
import queue

q = queue.Queue()
A = [[]*101 for _ in range(101)]
d = [-1]*101
visited = [False]*101

n = int(input().rstrip())
for i in range(n):
    line = [int(j) for j in input().rstrip().split()]
    A[i+1].extend(line[2:])

d[1] = 0

q.put(1)
while not q.empty():
    v = q.get()
    if visited[v] == True:
        continue
    visited[v] = True
    for i in A[v]:
        if d[i] == -1:
            d[i] = d[v] + 1
        else:
            d[i] = min(d[i],d[v] + 1)
        q.put(i)
        
for i in range(n):
    print(str(i+1)+" "+str(d[i+1]))

Python: import queue

n = int(input())

Graph = [[x-1 for x in list(map(int, input().split()))[2:]] for i in range(n)]


# for i in range(n):
#     li = list(map(int, input().split()))
#     a = li[0]
#     a-=1
#     b = li[2:]
#     Graph[a].append(b)


dist = [-1]*n
q = queue.Queue()

dist[0] = 0
q.put(0)

while not q.empty():
    v = q.get()

    for nv in Graph[v]:
        if dist[nv] != -1: continue

        dist[nv] = dist[v] + 1
        q.put(nv)


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