Go: // BFS

package main

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

var scanner = bufio.NewScanner(os.Stdin)

var p = [15]int{}
var g = [13][4]int {
	// -1は存在しないマス目
	{2,-1,-1,-1},
	{2,5,-1,-1},{0,1,3,6},{2,7,-1,-1},
	{5,-1,-1,-1},{1,4,6,9},{2,5,7,10},{3,6,8,11},{7,-1,-1,-1},
	{5,10,-1,-1},{6,9,11,12},{7,10,-1,-1},
	{10,-1,-1,-1},
}

/*
　  ０ １ ２ ３ ４
 0 |／|／|  |／|／|
 1 |／|　|  |　|／|
 2 |　|　|  |　|　|
 3 |／|　|  |　|／|
 4 |／|／|  |／|／|
*/

var row = [13]int{0,1,1,1,2,2,2,2,2,3,3,3,4}
var col = [13]int{2,1,2,3,0,1,2,3,4,1,2,3,2}

type wolf struct {
	m [13]int
}

type pair struct {
	first wolf
	second int
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func print_board(board [13]int) {
	fmt.Println("--------------------------")
	fmt.Printf("        [%2d]\n", board[0])
	fmt.Printf("    [%2d][%2d][%2d]\n", board[1], board[2], board[3])
	fmt.Printf("[%2d][%2d][%2d][%2d][%2d]\n", board[4], board[5], board[6], board[7], board[8])
	fmt.Printf("    [%2d][%2d][%2d]\n", board[9], board[10], board[11])
	fmt.Printf("        [%2d]\n", board[12])
	fmt.Println("--------------------------")
}

func main() {
	for scanner.Scan() {
		p1, _ := strconv.Atoi(scanner.Text())
		if p1 == -1 {
			break
		}
		p[0]= p1
		scanner.Scan()
		buf1 := strings.Split(scanner.Text(), " ")
		p2, _ := strconv.Atoi(buf1[0])
		p3, _ := strconv.Atoi(buf1[1])
		p4, _ := strconv.Atoi(buf1[2])
		p[1], p[2], p[3] = p2, p3, p4
		scanner.Scan()
		buf2 := strings.Split(scanner.Text(), " ")
		p5, _ := strconv.Atoi(buf2[0])
		p6, _ := strconv.Atoi(buf2[1])
		p7, _ := strconv.Atoi(buf2[2])
		p8, _ := strconv.Atoi(buf2[3])
		p9, _ := strconv.Atoi(buf2[4])
		p[4], p[5], p[6], p[7], p[8] = p5, p6, p7, p8, p9
		scanner.Scan()
		buf3 := strings.Split(scanner.Text(), " ")
		p10, _ := strconv.Atoi(buf3[0])
		p11, _ := strconv.Atoi(buf3[1])
		p12, _ := strconv.Atoi(buf3[2])
		p[9], p[10], p[11] = p10, p11, p12
		scanner.Scan()
		p13, _ := strconv.Atoi(scanner.Text())
		p[12] = p13
		S := make(map[wolf]struct{})
		st := wolf{}
		for i := 0; i < 13; i++ {
			st.m[i] = p[i]
		}
		Q := make([]pair, 0)
		S[st] = struct{}{}
		Q = append(Q, pair{st, 0})
		yet := true
		for len(Q) > 0 {
			at := Q[0].first
			// print_board(at.m)
			cost := Q[0].second
			Q = Q[1:]
			ok := true
			for i :=1; i < 12; i++ {
				if at.m[i] != i {
					ok = false
				}
			}
			if ok {
				// print_board(at.m)
				yet = false
				fmt.Println(cost)
				break
			}
			now := cost
			for i := 0; i < 13; i++ {
				if at.m[i] != 0 {
					now += abs(row[i]-row[at.m[i]]) + abs(col[i]-col[at.m[i]])
				}
			}
			if now > 20 {
				continue
			}
			for i := 0; i < 13; i++ {
				if at.m[i] == 0 {
					for j := 0; j < 4; j++ {
						if ^g[i][j] != 0 {
							at.m[i], at.m[g[i][j]] = at.m[g[i][j]], at.m[i]
							if _, ok := S[at]; !ok {
								S[at] = struct{}{}
								Q = append(Q, pair{at, cost+1})
							}
							at.m[i], at.m[g[i][j]] = at.m[g[i][j]], at.m[i]
						}
					}
				}
			}
		}
		if yet {
			fmt.Println("NA")
		}
	}
}

C++: #include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <queue>
#include <map>
using namespace std;

typedef vector<int> VI;

int size[13] = {1, 2, 4, 2, 1, 4, 4, 4, 1, 2, 4, 2, 1};
int move[13][4] = {
  {2},
  {2, 5},
  {0, 1, 6, 3},
  {2, 7},
  {5},
  {1, 4, 6, 9},
  {2, 5, 7, 10},
  {3, 6, 8, 11},
  {7},
  {5, 10},
  {6, 9, 11, 12},
  {7, 10},
  {10}
};

VI v;
map<VI, int> mp;
map<VI, int> mp2;

void make(){
  VI goal;
  for(int i = 0 ; i < 13 ; i++){
    if(i == 0 || i == 12) goal.push_back(0);
    else goal.push_back(i);    
  }
  
  queue<VI> que;
  que.push(goal);
  mp2[goal] = 0;
  
  while(!que.empty()){
    VI q = que.front(); que.pop();    
    if(mp2[q] > 13) continue;
    for(int i = 0 ; i < 13 ; i++){
      if(q[i] != 0) continue;
      for(int j = 0 ; j < size[i] ; j++){
	VI t = q;
	swap(t[i], t[ move[i][j] ]);
	if(mp2.find(t) != mp2.end()) continue;	
	mp2[t] = mp2[q] + 1;	
	que.push(t);
      }
    }
  }
}
    


int bfs(){
  queue<VI> que;
  que.push(v);
  mp[v] = 0;  
  while(!que.empty()){
    VI q = que.front(); que.pop();    
    if(mp2.find(q) != mp2.end()){
      return mp2[q] + mp[q];
    }
    
    if(mp[q] > 8) continue;
    for(int i = 0 ; i < 13 ; i++){
      if(q[i] != 0) continue;      
      for(int j = 0 ; j < size[i] ; j++){
	VI t = q;
	swap(t[i], t[ move[i][j] ]);
	if(mp.find(t) != mp.end()) continue;
	mp[t] = mp[q] + 1;
	que.push(t);
      }
    }
  }
  return -1;
}

void init(){
  v.clear();
  mp.clear();  
}

int main(){
  make();
  int n;
  while(cin >> n){
    if(n == -1) break;
    
    init();
    
    v.push_back(n);
    for(int i = 0 ; i < 12 ; i++){ cin >> n; v.push_back(n); }
    
    int ans = bfs();
    if(ans == -1 || ans > 20) cout << "NA" << endl;
    else cout << ans << endl;
  }
  

  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

//#define int long long

typedef pair<int,int>pint;
typedef vector<int>vint;
typedef vector<pint>vpint;
typedef vector<vint>vvint;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define all(v) (v).begin(),(v).end()
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
template<class T,class U>void chmin(T &t,U f){if(t>f)t=f;}
template<class T,class U>void chmax(T &t,U f){if(t<f)t=f;}

const int dy[]={-1,0,1,0};
const int dx[]={0,-1,0,1};

int p[5][5]={{-1,-1,0,-1,-1},{-1,1,2,3,-1},{4,5,6,7,8},{-1,9,10,11,-1},{-1,-1,0,-1,-1}};
void bfs(vvint &a,map<vvint,int>&s){
    queue<vvint>que[2];
    que[0].push(a);
    s[a]=0;
    rep(i,10){
        while(que[i&1].size()){
            vvint a=que[i&1].front();
            que[i&1].pop();
            rep(y,5)rep(x,5){
                if(a[y][x]!=0)continue;
                rep(d,4){
                    int ny=y+dy[d],nx=x+dx[d];
                    if(ny<0||ny>=5||nx<0||nx>=5||a[ny][nx]<=0)continue;
                    swap(a[ny][nx],a[y][x]);
                    if(s.find(a)==s.end()){
                        s[a]=i+1;
                        que[(i+1)&1].push(a);
                    }
                    swap(a[ny][nx],a[y][x]);
                }
            }
        }
    }
}

signed main(){
    vvint a(5,vint(5,-1));
    while(cin>>a[0][2],a[0][2]!=-1){
        rep(i,3)cin>>a[1][i+1];
        rep(i,5)cin>>a[2][i];
        rep(i,3)cin>>a[3][i+1];
        cin>>a[4][2];

        vvint b(5,vint(5));
        rep(i,5)rep(j,5)b[i][j]=p[i][j];

        map<vvint,int>m1,m2;
        bfs(a,m1);
        bfs(b,m2);

        int ans=21;
        each(it,m1){
            if(m2.find(it->fi)==m2.end())continue;
            chmin(ans,it->se+m2[it->fi]);
        }
        if(ans<=20)cout<<ans<<endl;
        else cout<<"NA"<<endl;
    }
    return 0;
}