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())
g = [None] * n
visited = [0] * n
dist = [-1] * n
queue = deque()

while n:
    l = list(map(int, input().split()))
    connected = [i - 1 for i in l[2:]]
    g[l[0] - 1] = [i - 1 for i in l[2:]]
    n -= 1

queue.append((0, 0))
visited[0] = 1

while queue:
    print(queue)
    i, d = queue.popleft()
    dist[i] = d
    for c in g[i]:
        if not visited[c]:
            visited[c] = 1
            queue.append((c, d + 1))

for i, d in enumerate(dist):
    print(i + 1, d)

Python: n = int(input())

A = [[] for i in range(n)]

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

f_inf = float("inf")
B = [[f_inf for i in range(2)] for j in range(n)]
B[0][1] = 0

for i in range(n):
  B[i][0] = i+1

def dbs(a):
  global order
  l = len(A[a-1])-2
  if l:
    for i in range(l):
      depth = B[a-1][1]+1
      b = A[a-1][i+2]
      if not b in order or depth < B[b-1][1]:
        B[b-1][1] = depth
        order.append(b)
        dbs(b)

order = [1]
dbs(1)

for i in range(n):
  if B[i][1] == f_inf:
    B[i][1] = -1
  print(" ".join(map(str, B[i])))

Python: # 28
# ALDS_11_C - 幅優先探索

from collections import deque

n = int(input())
u_l = []
k_l = []
v_l = []

for i in range(n):
    _v_l = []
    for j, _ in enumerate(input().split()):
        if j == 0:
            u_l.append(int(_))
        elif j == 1:
            k_l.append(int(_))
        else:
            _v_l.append(int(_))
    v_l.append(_v_l)
        
d_l = [-1]*n
d_l[0] = 0
s_dq = deque([1])
while len(s_dq) > 0:
    _s = s_dq.popleft()
    _s -= 1
    for i in range(k_l[_s]):
        _v = v_l[_s][i]
        if d_l[_v-1] == -1:
            s_dq.append(_v)
            d_l[_v-1] = d_l[_s] + 1

for _id, _d in zip(range(1,n+1), d_l):
    print(_id, _d)

Python: from collections import deque
def bfs(g,v):
    q=deque([v]) ; vis=[0]*n
    vis[v]=1 ; stg[v]=0
    while q:
        v=q[0]
        for p in g[v]:
            if vis[p]==0: 
                q.append(p)
                vis[p]=1
                stg[p]=stg[v]+1
        q.popleft()
n=int(input())
g=[[] for i in range(n)]
for _ in range(n):
    a=[int(i)-1 for i in input().split()]
    for i in a[2:]: g[a[0]].append(i)
stg=[-1]*n
bfs(g,0)
for i in range(n):
    print(i+1,stg[i])

Python: from collections import deque

def main():

    inf = 1000000007
    n = int(input())
    e = [[] for _ in range(n)]
    d = [inf]*n

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

    d[0] = 0
    dq = deque([])
    dq.append([0,0])
    while dq:
        c,v = dq.popleft()
        for u in e[v]:
            if d[u]==inf:
                d[u] = c+1
                dq.append([c+1,u])

    for i in range(n):
        if d[i]==inf:print (i+1,-1)
        else        :print (i+1,d[i])

if __name__ == '__main__':
    main()

Python: n=int(input())
ps=[0 for j in range(n+1)]

for i in range(n):
    p,d,*vs=[int(j) for j in input().split()]
    ps[p]=vs
    
dist=[-1 for i in range(n+1)]    
    
d=0
queue=[1]

while queue:
    pos=queue.pop(0)
    if dist[pos] == -1:
        dist[pos]=d
    for i in ps[pos]:
        if dist[i]==-1:
            queue.append(i)
            dist[i]=dist[pos]+1

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

Python: from collections import deque

n = int(input())
u = [[] for i in range(n+1)] #隣接リスト
for i in range(n):
    v = list(map(int, input().split()))
    u[v[0]] = v[1:] #v = [次数, 頂点...]

d = [-1] * (n+1)
visited = [False] * (n+1)

d[1] = 0
visited[1] = True
que = deque([1])
while len(que) > 0:
    c = que.popleft()
    for i in range(1, u[c][0]+1):
        if not visited[u[c][i]]:
            que.append(u[c][i])
            visited[u[c][i]] = True
            d[u[c][i]] = d[c] + 1

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

Python: from collections import deque

n = int(input())
graph_W = []
for _ in range(n):
    graph_W.append(list(map(int, input().split())))
    
num_root = [0]*n
work_queue = deque([])
visited = set()

work_queue.append(1)
visited.add(1)
cnt = 0
while work_queue:
    here = work_queue.popleft() - 1
    num_node = graph_W[here][1]
    cnt += 1
    if num_node == 0:
        continue
    for k in range(num_node):
        num_graph = graph_W[here][k+2]
        if num_graph not in visited:
            work_queue.append(num_graph)
            visited.add(num_graph)
            num_root[num_graph-1] = num_root[here] + 1


print(1,0)
for i in range(1,n):
    if num_root[i] != 0:
        print(i+1,num_root[i])
    else:
        print(i+1,-1)

Python: from collections import deque

INF = 1e9

def BFS(n, adj):
    d = [INF] * N
    d[0] = 0
    next_v = deque([0]) # ?¬??????????????????????
    
    while next_v:
        u = next_v.popleft()
        
        for v in adj[u]:
            if d[v] == INF:
                d[v] = d[u] + 1
                next_v.append(v)
    
    return d

N = int(input())
Adj = [None] * N

for i in range(N):
    u, k, *vertex = [int(i)-1 for i in input().split()]
    Adj[u] = vertex

distance = BFS(N, Adj)

for i, di in enumerate(distance, start = 1):
    if di == INF:
        print(i, -1)
    else:
        print(i, di)

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


while Q:top = Q.pop();func(top)

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

Python: 
def BFS(s = 0):
    Q.pop(0)
    color[s] = 2
    for j in range(len(color)):
        if A[s][j] == 1 and color[j] == 0:
            Q.append(j)
            color[j] = 1
            d[j] = d[s] + 1
    if len(Q) != 0:
        BFS(Q[0])

n = int(raw_input())
A = [0] * n
for i in range(n):
    A[i] = [0] * n

for i in range(n):
    value = map(int, raw_input().split())
    u = value[0] - 1
    k = value[1]
    nodes = value[2:]
    for j in range(k):
        v = nodes[j] - 1
        A[u][v] = 1

color = [0] * n
Q = [0]
d = [-1] * n
d[0] = 0

BFS(0)

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