Go: package main

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

var scanner = bufio.NewScanner(os.Stdin)

func nextString() string {
	scanner.Scan()
	return scanner.Text()
}

func nextInt() int {
	n, err := strconv.Atoi(nextString())
	if err != nil {
		fmt.Printf("strconv.Atoi failed: %v\n", err)
	}
	return n
}

func stringifyArray(arr []int) string {
	return strings.TrimRight(fmt.Sprintf("%+v", arr)[1:], "]")
}

var infty = 1000000000

type nodeKey int

type DirectedGraphNode struct {
	key       nodeKey
	adjacents []*DirectedGraphNode
	visited   bool
	d         int
	parent    *DirectedGraphNode
}

type DirectedGraph struct {
	nodes []DirectedGraphNode
}

func (g *DirectedGraph) setAdjacency(l, r nodeKey) {
	g.nodes[l].adjacents = append(g.nodes[l].adjacents, &g.nodes[r])
}

func newDirectedGraph(nNodes int) *DirectedGraph {
	graph := DirectedGraph{}
	graph.nodes = make([]DirectedGraphNode, nNodes)
	for iNodes := 0; iNodes < nNodes; iNodes++ {
		graph.nodes[iNodes].key = nodeKey(iNodes)

		graph.nodes[iNodes].visited = false
		graph.nodes[iNodes].d = infty
		graph.nodes[iNodes].parent = nil
	}
	return &graph
}

type QueueEntry struct {
	node *DirectedGraphNode
	next *QueueEntry
}

type Queue struct {
	head, tail *QueueEntry
}

func (q *Queue) enqueue(node *DirectedGraphNode) {
	entry := QueueEntry{}
	entry.node = node

	if q.tail == nil {
		q.head = &entry
		q.tail = &entry
		return
	}

	q.tail.next = &entry
	q.tail = q.tail.next
}

func (q *Queue) dequeue() *QueueEntry {
	if q.head == nil {
		return nil
	}
	poped := q.head
	q.head = q.head.next
	if q.head == nil {
		q.tail = nil
	}
	return poped
}

func (q *Queue) isEmpty() bool {
	return q.head == nil
}

func fillDistancesByBreadthFirstSearch(g *DirectedGraph, startNode *DirectedGraphNode) {
	startNode.visited = true
	startNode.d = 0

	queue := Queue{}
	queue.enqueue(startNode)
	for !queue.isEmpty() {
		u := queue.dequeue().node
		for _, adjacent := range u.adjacents {
			if !adjacent.visited {
				adjacent.visited = true
				adjacent.d = u.d + 1
				adjacent.parent = u
				queue.enqueue(adjacent)
			}
		}
		u.visited = true
	}
}

func main() {
	scanner.Split(bufio.ScanWords)

	nNodes := nextInt()
	g := newDirectedGraph(nNodes + 1)

	for iNode := 0; iNode < nNodes; iNode++ {
		nodeKeyLeft := nodeKey(nextInt())
		nAdj := nextInt()
		for iAdj := 0; iAdj < nAdj; iAdj++ {
			nodeKeyRight := nodeKey(nextInt())
			g.setAdjacency(nodeKeyLeft, nodeKeyRight)
		}
	}

	// fmt.Println(g)
	fillDistancesByBreadthFirstSearch(g, &g.nodes[1])
	// fmt.Println(g)

	for iNode := 1; iNode <= nNodes; iNode++ {
		node := g.nodes[iNode]
		distance := node.d
		if distance == infty {
			distance = -1
		}
		fmt.Println(node.key, distance)
	}
}

C++: #include <iostream>
#include <vector>
#include <queue>
using namespace std;

vector<int> bfs(vector<vector<int>> &adj_list)
{
    vector<int> res(adj_list.size(), -1);
    vector<bool> visit(adj_list.size(), 0);
    queue<int> q;
    q.push(0);
    visit[0] = 1;
    res[0] = 0;

    while (!q.empty())
    {
        int u = q.front();
        q.pop();
        for (int i = 0; i < adj_list[u].size(); i++)
        {
            int v = adj_list[u][i];
            if (visit[v] == 0)
            {
                visit[v] = 1;
                res[v] = res[u] + 1;
                q.push(v);
            }
        }
    }

    return res;
}

int main()
{
    int n;
    cin >> n;

    vector<vector<int>> adj_list(n);
    for (int i = 0; i < n; i++)
    {
        int id, k;
        cin >> id >> k;
        for (int j = 0; j < k; j++)
        {
            int u;
            cin >> u;
            adj_list[id - 1].push_back(u - 1);
        }
    }

    // for (int i = 0; i < n; i++)
    // {
    //     for (int j = 0; j < adj_list[i].size(); j++)
    //     {
    //         cout << adj_list[i][j] << ", ";
    //     }
    //     cout << endl;
    // }

    vector<int> res = bfs(adj_list);
    for (int i = 0; i < n; i++)
    {
        cout << i + 1 << " " << res[i] << endl;
    }

    return 0;
}

C++: /*
?????????: Graph I - Breadth First Search
URL: http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_11_C
?????°
19:08 ??°?????????????????????????????£??¨??????????????????????????§???????????????????????£?????????
19:08 ???????????\????????\????????°??????????????????????¢????
19:09 ????????°???????????????????§£
19:13 ??¨???????????????????????£???
19:19 BFS????¨???¶???????¶??????????????????§??¨?????????????????????????????????
19:28 ???????????????????§?????????????????????£????????§????????????????????????????????????????????§????????????????????£????????????
19:29 ?????????????????????????????????????????? 1 ????????????????????????????????????????????????????????¢??¨??????-1 ?????????????????????????????????
*/
#include <iostream>
#include <vector>
#include <set>
#include <queue>
#define INF 114514
using namespace std;

int main()
{
	int n; cin>>n;
	vector< set<int> > graphdat(n+1);  
	for(int i=0;i<n;i++){
		int u; int k; cin >> u >> k;
		set<int> v;
		for(int j=0;j<k;j++){
			int tmp;
			cin >> tmp;
			v.insert(tmp);
		}
		graphdat[u] = v;
	}

	vector<int> distance(n+1);
	distance[1] = 0;
	for(int i=2;i<=n;i++){
		distance[i] = INF;
	}

	queue<int> Q;
	Q.push(1);

	while(!Q.empty()) {
		int cur = Q.front();
		Q.pop(); // pop?????????????????????????????¨?¬???\??§??????
		for(int dest=1; dest<=n; dest++) {
			if(graphdat[cur].find(dest) != graphdat[cur].end()) { // ??????????????????
				if(distance[dest] > distance[cur] + 1) { // ??´??°??§????????????
					distance[dest] = distance[cur] + 1;
					Q.push(dest);
				}
			}
		}
	}

	for(int i=1;i<=n;i++){
		cout << i << " " << (distance[i] == INF ? -1 : distance[i])<< endl;
	}

}

C++: #include <cstdio>
#include <iostream>
#include <queue>
using namespace std;

static const int MAX_NUM = 101;
static const int NO_VISIT  = 0;
//static const int NOW_VISIT = 1;
static const int END_VISIT = 2;

void BFS(int *matrix, int num)
{
    int i;
    int state[MAX_NUM]    = {0};
    int distance[MAX_NUM];
    queue<int> Q;
    int target;
    int dist = 0;
    int *tmp;
    bool first;

    for (i = 1; i <= num; i++) {
        distance[i] = -1;
    }

    Q.push(1);
    state[1] = END_VISIT;
    distance[1] = 0;

    while (Q.empty() == false) {
        target = Q.front();
        Q.pop();
        tmp = matrix + target * MAX_NUM;
        first = true;
        for (i = 1; i <= num; i++) {
            if ((*(tmp + i) == 1) && (state[i] == NO_VISIT)) {
                distance[i] = distance[target] + 1;
                Q.push(i);
                state[i] = END_VISIT;
            }
        }
    }

    for (i = 1; i <= num; i++) {
        printf("%d %d\n", i, distance[i]);
    }

    return;
}

int main(void)
{
    int i, j;
    int num;
    int elem;
    int nume;
    int tmp;
    int matrix[MAX_NUM][MAX_NUM];

    scanf("%d", &num);
    for (i = 0; i < num; i++) {
        scanf("%d %d", &elem, &nume);
        for (j = 0; j < nume; j++) {
            scanf("%d", &tmp);
            matrix[elem][tmp] = 1;
        }
    }

    BFS(&matrix[0][0], num);

    return 0;
}