Go: package main

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

//util
var sc = bufio.NewScanner(os.Stdin)

func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func printList(list []int) {
	n := len(list)
	buf := bufio.NewWriter(os.Stdout)
	for _, v := range list[0 : n-1] {
		buf.Write([]byte(fmt.Sprintf("%d ", v)))
	}
	buf.Write([]byte(fmt.Sprintf("%d\n", list[n-1])))
	buf.Flush()
}

func max(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func min(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

//solve
const INFTY = (1 << 21)
const MAX = 100
const WHITE = 0
const GRAY = 1
const BLACK = 2

var time, n int

//隣接行列
var M [MAX][MAX]int

//d[i]: 頂点1から頂点iまでの距離
var color, d [MAX]int

func bfs(s int) {
	var q []int
	q = append(q, s)
	for i := 0; i < n; i++ {
		d[i] = INFTY
	}
	//sは開始点なので、0をいれる
	d[s] = 0

	//キューが空になるまで、以下を繰り返す
	for len(q) > 0 {
		u := q[0]
		q = q[1:]
		for v := 0; v < n; v++ {
			if M[u][v] == 0 {
				continue
			}
			if d[v] != INFTY {
				continue
			}
			d[v] = d[u] + 1
			q = append(q, v)
		}
	}

	for i := 0; i < n; i++ {
		fmt.Printf("%d ", i+1)
		if d[i] == INFTY {
			fmt.Printf("%d\n", -1)
		} else {
			fmt.Printf("%d\n", d[i])
		}
	}
}

func main() {
	sc.Split(bufio.ScanWords)
	n = nextInt()
	for i := 0; i < n; i++ {
		u, k := nextInt(), nextInt()
		M[u-1][u-1] = 0

		//fmt.Println(u, k)
		if k > 0 {
			for j := 0; j < k; j++ {

				v := nextInt()
				M[u-1][v-1] = 1

			}
		}

	}

	bfs(0)

}

Python: n = int(input())

m = [[0 for _ in range(n+1)] for _ in range(n+1)]
mm = [[] 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:]
	mm[u] += tmp[2:]
	for x in l:
		m[u][x] = 1
		
dp = [float('inf') for _ in range(n+1)]
dp[1] = 0
queue = [1]

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

while queue:
	t = queue.pop(0)
	for x in mm[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: def srch(i, l, Lng, Dst):
    if Lng[i] != -1 and Lng[i] < l:
        return
    Lng[i] = l
    if Dst[i] is not None and len(Dst[i]) > 0:
        for c in Dst[i]:
            srch(c,l+1, Lng, Dst)

def main():
    num = int(input())
    Dst = [None for i in range(num + 1)]
    Lng = [-1] * (num + 1)
    
    for n in range(1, num+1):
        a = list(map(int,input().split()))
        u = a[0]
        if a[1] > 0:
            Dst[u] = a[2:]

    srch(1, 0, Lng, Dst)

    for n in range(1, num+1):
        l = Lng[n]
        if l > num:
            l = -1
        print("{} {}".format(n,l))

if __name__ == '__main__':
    main()

Python: # -*- coding: utf-8 -*-
"""
Created on Sun Jul  8 10:56:33 2018

@author: maezawa
"""
n = int(input())
adj = [[] for _ in range(n)]
d = [-1 for _ in range(n)]
d[0] = 0


for j in range(n):
    ain = list(map(int, input().split()))
    u = ain[0]
    k = ain[1]
    for i in range(k):
        adj[u-1].append(ain[i+2]-1)
    adj[u-1].sort()
    #print(*adj[u-1])

stack = [0]

while stack:
    print(stack)
    current = stack[-1]
    flag = 0
    for k in adj[current]:
        if d[k] <= 0:
            d[k] = d[current]+1
            stack.append(k)
            flag = 1
    if flag == 0:
        stack.pop()

    #print('current = {}, t = {}'.format(current, t))
    #print('stack', *stack)

for i in range(n):
    print('{} {}'.format(i+1, d[i]))

Python: from collections import deque
n = int(input())
u = []
k = []
v = []

for i in range(n):
    tmp = list(map(int, input().split()))
    u.append(tmp[0])
    k.append(tmp[1])
    if tmp[1] != 0:
        v.append(tmp[2:])
    else:
        v.append([])
        
d = deque([1])
dis = [-1]*n
dis[0] = 0
visit = [False]*n
visit[0] = True
while len(d) > 0:
    go = d[0]
    flag = False
    for i in v[go-1]:
        if not visit[i-1]:
            d.append(i)
            dis[i-1] = dis[go-1] + 1
            visit[i-1] = True
            flag = True
    d.popleft()
    
for i in range(n):
    print(i+1, dis[i])

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]))