Go: package main

/*
グラフの表現 隣接行列による表現
*/

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

func main() {
	scanner := makeScanner(8192)
	n := eGetInt(scanner)
	g := make([][]int, n+1)
	for i := 1; i < n+1; i++ {
		g[i] = make([]int, n+1)
		ints := eGetInts(scanner)
		num := ints[0]
		for j := 0; j < ints[1]; j++ {
			g[num][ints[j+2]] = 1
		}
	}
	dist := make([]int, n+1)
	for i := 0; i < len(dist); i++ {
		dist[i] = -1
	}
	q := []int{}

	// 訪問する
	q = append(q, 1)
	dist[1] = 0

	// キューが空でない限り
	for len(q) > 0 {
		// 先頭を取り出す
		top := 0
		top, q = q[0], q[1:]
		// 隣接マスを入れる.
		for i := 1; i < n+1; i++ {
			// 辺がある
			if g[top][i] == 1 {
				if dist[i] == -1 {
					// 訪問済みでなければ
					q = append(q, i)
					dist[i] = dist[top] + 1
				}
			}
		}
	}
	for i := 1; i < n+1; i++ {
		fmt.Println(i, dist[i])
	}
}

////////////////////////////////////////////////////////////////////////////////
// ライブラリ
////////////////////////////////////////////////////////////////////////////////
func makeScanner(maxByte int) *bufio.Scanner {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Buffer(make([]uint8, 0, 8192), maxByte)
	return scanner
}
func makeWordScanner() *bufio.Scanner {
	scanner := makeScanner(8192)
	scanner.Split(bufio.ScanWords)
	return scanner
}
func eGetLine(r *bufio.Scanner) string {
	if r.Scan() {
		return r.Text()
	}
	err := r.Err()
	if err != nil {
		log.Fatal(err)
	}
	// EOF
	return ""
}
func eGetInt(r *bufio.Scanner) int {
	line := eGetLine(r)
	return eAtoi(line)
}
func eGetInt64(r *bufio.Scanner) int64 {
	line := eGetLine(r)
	return eAtoInt64(line)
}
func eGetFields(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Fields(line)
}
func eGetInts(r *bufio.Scanner) []int {
	fields := eGetFields(r)
	ints := make([]int, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoi(fields[i])
	}
	return ints
}
func eGetInt64s(r *bufio.Scanner) []int64 {
	fields := eGetFields(r)
	ints := make([]int64, len(fields))
	for i := 0; i < len(ints); i++ {
		ints[i] = eAtoInt64(fields[i])
	}
	return ints
}
func eGetChars(r *bufio.Scanner) []string {
	line := eGetLine(r)
	return strings.Split(line, "")
}
func eAtoi(s string) int {
	n, err := strconv.Atoi(s)
	if err != nil {
		log.Fatal(err)
	}
	return n
}
func eAtoInt64(s string) int64 {
	n, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		log.Fatal(err)
	}
	return n
}

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 = [10000 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] == 10000:
       dis[s] = -1
for s in range(n):
    print (s+1, d[s])

Python: 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(raw_input())
  
G = [0 for i in range(n)] 
a = [[0 for i in range(n)] for j in range(n)]
dis = [-1 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] == -1:
         dis[k] = dis[s] + 1
         bfs_visit(k)
 
for s in range(n):
    bfs_visit(s)
for s in range(n):
    print (s+1,dis[s])

Python: class Node(object):
    def __init__(self, V):
        self.V = V
        self.d = -1 
  
n = int(input())
nodes = [0] * 101
for i in range(n):
    data = input().split()
    V = list(map(int, data[2:]))
    V.sort(reverse = True)
    nodes[int(data[0])] = Node(V)
  
l = [1,]
l_old = []
cnt = 0

while len(l) > 0:
    l_old = l
    l = []
    for i in l_old:
        nodes[i].d = cnt
        V = nodes[i].V
        for j in V:
            if not j in l:
                if nodes[j].d == -1:
                    l.append(j)
    cnt += 1
                

for i in range(1, n+1):
    if not isinstance(nodes[i], int):
        print(i, nodes[i].d)

Python: from collections import deque
n = int(input())
M = [[0]*n for _ in range(n)]
d = [-1]*n
st = [0]*n
for _ in range(n):
    i = [int(i) for i in input().split()]
    u = i[0]
    k = i[1]
    V = i[2:]
    for v in V: M[u-1][v-1] = 1

def bfs(s):
    Q = deque()
    Q.append(s)
    st[s] = 1
    d[s] = 0
    while Q:
        u = Q.popleft()
        for v in range(n):
            if M[u][v] and st[v] == 0:
                st[v] = 1
                Q.append(v)
                d[v] = d[u]+1
        st[u] = 2
    return

bfs(0)
for i in range(n): print(i+1,d[i])

Python: from collections import deque

n = int(input())

adj = [0]*n # adjacent list
d = [-1]*n # distance from the source vertex
c = ['w']*n # the 'color' of each vertex

# receiving input (the structure of the graph)
for i in range(n):
    tmp = list(map( int, input().split() ) )
    adj[tmp[0]-1] = list(map(lambda x : x - 1, tmp[2:]))

# set the source vertex
s = 0
d[s] = 0
c[s] = 'g'


Q = deque()
Q.append(s)

while Q:
    u = Q.popleft()
    for v in adj[u]:
        if c[v] == 'w':
            c[v] = 'g'
            d[v] = d[u] + 1
            Q.append(v)
    c[u] = 'b'
    

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

Python: from sys import stdin
from collections import deque
n = int(stdin.readline())
d = [-1] * (n + 1)
def bfs(G):
    d[1] = 0
    dq = deque([1])
    while len(dq) > 0:
        v = dq.popleft()
        for c in G[v]:
            if d[c] < 0:
                d[c] = d[v] + 1
                dq.append(c)
    for i, x in enumerate(d[1:], start=1):
        print(i, x)
G = [0]
for i in range(n):
    G.append(list(map(int, stdin.readline().split()[2:])))
bfs(G)

Python: def BFS(G):
    ans = [0] + [[i+1,-1] for i in range(len(G))]
    def main(G,i,d):
        ans[i] = [i, d]
        for j in G[i-1][2:]: main(G,j,d+1)
    main(G,1,0)
    return ans[1:]


if __name__=='__main__':
    n = int(input())
    G = [list(map(int,input().split())) for _ in range(n)]
    for out in BFS(G): print(*out)

Python: n = int(input())
G = [[0]]+[list(map(int, input().split()))[2:] for _ in range(n)]
# print(G)
from collections import deque
d = deque([1])
dist  = [10**10 for _ in range(n+1)]
dist[1] = 0
while len(d) != 0:
    now = d.popleft()
    # print(now)
    for nexte in G[now]:
        if dist[now] +1 < dist[nexte]:
            dist[nexte] = dist[now] + 1
            d.append(nexte)
for i,d in enumerate(dist[1:]):
    if d != 10**10:
        print(i+1,d)
    else:
        print(i+1,-1)