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())
}

C++: #include <iostream>
#include <queue>

using namespace std;

int D[100100];//始点からの距離を入れる
int g[1001][1001]={{0}};//要素を0で初期化
void bfs(int src,int n){//srcは開始位置この場合だと頂点1だから0
  cerr << "bfs_root = " << src << endl;
  queue<int> Q;
  Q.push(src);
  D[src] = 0;
  while (! Q.empty()  ){
    int cur = Q.front();
    Q.pop();
    // cerr << "visiting_" << cur << " " <<D[cur] <<endl;
    for(int dst= 0; dst < n; dst++){
      if(g[cur][dst]==1 && D[dst]==0){
        D[dst]=D[cur]+1;
        Q.push(dst);
      }
    }
  }
}
void ans(int n){
  for (int i = 0; i < n; ++i)
  {
    cout << i+1 <<D[i]<<endl;
  }

}

int main(){
  // int g[1001][1001]={{0}};//要素を0で初期化
  int n,a,b,c;
  cin >> n;
  for (int i = 0; i < n; ++i)
  {
    cin >> a >> b ;
    for (int i = 0; i < b; ++i)
    {
      cin >> c;
      g[a-1][c-1]=1;/* code */
    }
  }
  bfs(0,n);
  ans(n);
  // for (int i = 0; i < n; ++i)
  // {
  //    for (int j = 0; j < n; ++j)
  //    {
  //     if (j==n-1)
  //     {
  //       cout << g[i][j] << endl;
  //     }else{
  //       cout << g[i][j] <<" ";
  //     }
  //    }
  // }


}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cassert>
#include <string>
#include <cstring>
#include <vector>
#include <list>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <algorithm>

using namespace std;

// ---------------------
// repetition
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)

// debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

// ---------------------
#define INF 922337203685477580
typedef long long ll;

int matrix[110][110];
int dist[110];
int n;
queue<int> Q;

int main() {
  REP(x, 110) {
    REP(y, 110) {
      matrix[x][y] = 0;
    }
    dist[x] = (1 << 15);
  }

  // int n;
  cin >> n;

  REP(_, n) {
    int v, num;
    cin >> v >> num;

    REP(i, num) {
      int cv;
      cin >> cv;
      matrix[v][cv] = 1;
    }
  }

  dist[1] = 0;
  Q.push(1);

  while (!Q.empty()) {
    int f = Q.front(); Q.pop();

    FOR(v, 1, n + 1) {
      if (matrix[f][v]) {
        Q.push(v);
        dist[v] = min(dist[v], dist[f] + 1);
      }
    }
  }


  FOR(v, 1, n + 1) {
    cout << v << " " << dist[v] << endl;
  }


  return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

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

  vector<vector<int>> adjacent(n);
  for (int i = 0; i < n; i++) {
    int u, k;
    cin >> u >> k;
    --u;

    for (int i = 0; i < k; i++) {
      int v;
      cin >> v;
      --v;

      adjacent[u].push_back(v);
    }
  }

  vector<int> d(n, -1);
  vector<bool> pushed(n, false);
  queue<int> Q;

  Q.push(0);
  
  pushed[0] = true;
  
  d[0] = 0;

  while (!Q.empty()) {
    int u = Q.front();

    int parentDist = d[u];

    for (int i = 0; i < adjacent[u].size(); i++) {
      int v = adjacent[u][i];

      if (!pushed[v]) {
        Q.push(v);
        pushed[v] = true;
        d[v] = parentDist + 1;
      }
    }

    Q.pop();
  }

  for (int i = 0; i < n; i++) {
    cout << i + 1 << " " << d[i] << endl;
  }

  return 0;
}

C++: #include <iostream>
#include <vector>
#include <stack>
#include <queue>
#include <utility>

using vvi = std::vector<std::vector<int>>;

std::vector<int> DistanseFrom(const vvi& edges, int from)
{
    using namespace std;
    constexpr int nil = -1;

    int nextDist {};
    const int n = edges.size();
    queue<int> currentQ;
    queue<int> nextQ;
    vector<int> distances(n, nil);

    nextQ.push(from);
    distances[from] = nextDist;
    ++nextDist;

    while (!nextQ.empty())
    {
        currentQ = nextQ;
        nextQ = queue<int>();
        
        while (!currentQ.empty())
        {
            int c = currentQ.front();
            currentQ.pop();

            for (const auto& e : edges[c])
            {
                if (distances[e] == nil)
                {
                    nextQ.push(e);
                    distances[e] = nextDist;
                }
            }
        }
        
        ++nextDist;
    }

    return distances;
}

void solve()
{
    using namespace std;

    int n;
    cin >> n;

    //隣接リスト形式(1オリジン)
    vvi edges(n + 1);

    //読み込み
    for (int i = 1; i <= n; ++i)
    {
        int u, k;
        cin >> u >> k;

        edges[u] = vector<int>(k);

        for (int j = 0; j < k; ++j)
        {
            cin >> edges[u][j];
        }
    }

    auto dist = DistanseFrom(edges, 1);

    for (int i = 1; i <= n; ++i)
    {
        cout << i << " " << dist[i] << endl;
    }
}

int main()
{
    solve();
    return 0;
}