Go: package main

import (
	"fmt"
	"math"
)

type Position struct {
	X int64
	Y int64
}

func (one Position) Distance(another Position) int64 {
	return int64(math.Abs(float64(one.X-another.X)) + math.Abs(float64(one.Y-another.Y)))
}

type PersonPosition struct {
	Takayuki Position
	Kazuyuki Position
}

func (one PersonPosition) Distance() int64 {
	return one.Takayuki.Distance(one.Kazuyuki)
}

type Status struct {
	Person PersonPosition
	Turn   int64
}

type PQStatus []*Status

func (pq PQStatus) Len() int {
	return len(pq)
}
func (pq PQStatus) Less(i, j int) bool {
	if pq[i].Turn == pq[j].Turn {
		return pq[i].Person.Distance() < pq[j].Person.Distance()
	}
	return pq[i].Turn < pq[j].Turn
}

func (pq PQStatus) Swap(i, j int) {
	pq[i], pq[j] = pq[j], pq[i]
}

func (pq *PQStatus) Push(x interface{}) {
	item := x.(*Status)
	*pq = append(*pq, item)
}

func (pq *PQStatus) Pop() interface{} {
	old := *pq
	n := len(old)
	item := old[n-1]
	*pq = old[0 : n-1]
	return item
}

func solve(h, w int64) {
	var tx, ty, kx, ky int64
	fmt.Scan(&tx, &ty, &kx, &ky)
	tx--
	ty--
	kx--
	ky--
	m := make([][]int64, h)
	for i := range m {
		m[i] = make([]int64, w)
		for j := int64(0); j < w; j++ {
			fmt.Scan(&m[i][j])
		}
	}
	start := &Status{Person: PersonPosition{Takayuki: Position{X: tx, Y: ty}, Kazuyuki: Position{X: kx, Y: ky}}, Turn: 0}
	pq := make(PQStatus, 0)
	//heap.Init(&pq)
	//heap.Push(&pq, start)
	//pq.Push(start)
	pq = append(pq, start)
	dx := []int64{0, 1, 0, -1}
	dy := []int64{1, 0, -1, 0}
	memo := make(map[PersonPosition]int64, 0)
	ans := int64(102)
	for pq.Len() > 0 {
		//now := heap.Pop(&pq).(*Status)
		//now := pq.Pop().(*Status)
		now := pq[0]
		pq = pq[1:]
		if now.Person.Distance() == 0 && ans > now.Turn {
			ans = now.Turn
		}
		if ans <= now.Turn {
			continue
		}

		if _, ok := memo[now.Person]; ok {
			continue
		}
		memo[now.Person] = now.Turn

		for i := 0; i < 4; i++ {
			next := &Status{}
			*next = *now
			next.Person.Kazuyuki.X += dx[i]
			next.Person.Kazuyuki.Y += dy[i]
			if next.Person.Kazuyuki.X < 0 || next.Person.Kazuyuki.X >= w ||
				next.Person.Kazuyuki.Y < 0 || next.Person.Kazuyuki.Y >= h ||
				m[next.Person.Kazuyuki.Y][next.Person.Kazuyuki.X] == 1 {
				next.Person.Kazuyuki.X -= dx[i]
				next.Person.Kazuyuki.Y -= dy[i]
			}
			next.Person.Takayuki.X -= dx[i]
			next.Person.Takayuki.Y -= dy[i]
			if next.Person.Takayuki.X < 0 || next.Person.Takayuki.X >= w ||
				next.Person.Takayuki.Y < 0 || next.Person.Takayuki.Y >= h ||
				m[next.Person.Takayuki.Y][next.Person.Takayuki.X] == 1 {
				next.Person.Takayuki.X += dx[i]
				next.Person.Takayuki.Y += dy[i]
			}
			next.Turn++
			if next.Turn <= 100 {
				//heap.Push(&pq, next)
				//pq.Push(next)
				pq = append(pq, next)
			}
		}
	}
	if ans == 102 {
		fmt.Println("NA")
	} else {
		fmt.Println(ans)
	}
}

func main() {
	var h, w int64
	for {
		fmt.Scan(&h, &w)
		if h == 0 && w == 0 {
			break
		}
		solve(h, w)
	}
}

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

using namespace std;
#define MAX 64

typedef pair<int,int> pi;

const int di[] = {-1,0,1,0};
const int dj[] = {0,1,0,-1};

bool isinside(pi pos, int H, int W){
  return 0<=pos.first&&pos.first<H&&0<=pos.second&&pos.second<W;
}
class State{
public:
  pi taka;
  pi kazu;
  int time;
  State( pi taka, pi kazu, int t ):taka(taka),kazu(kazu),time(t){}
};

int bfs(int sti, int stj, int ski, int skj, int H, int W, bool M[][MAX]){
  static bool vis[50][50][50][50];
  for(int i = 0; i < H; ++i){
    for(int j = 0; j < W; ++j){
      for(int k = 0; k < H; ++k){
	for(int l = 0; l < W; ++l){
	  vis[i][j][k][l] = false;
	}
      }
    }
  }

  State st(pi(sti,stj),pi(ski,skj),0);
  queue<State> qs;
  qs.push( st );
  vis[sti][stj][ski][skj]=true;
  while(!qs.empty()){
    State now = qs.front();
    qs.pop();
    //cout << now.taka.first << ' ' << now.taka.second << ' ' << now.kazu.first << ' ' << now.kazu.second << endl;
    if( now.taka.first == now.kazu.first && now.taka.second == now.kazu.second ){
      return now.time;
    }
    for(int k = 0; k < 4; ++k){
      pi ntaka( now.taka.first+di[k], now.taka.second+dj[k] );
      pi nkazu( now.kazu.first+di[(k+2)%4], now.kazu.second+dj[(k+2)%4]);

      if( !isinside(ntaka,H,W ) ){
	ntaka = now.taka;
      }else{
	if( M[ntaka.first][ntaka.second] )
	  ntaka = now.taka;
      }

      if( !isinside(nkazu,H,W ) ){
	nkazu = now.kazu;
      }else{
	if( M[nkazu.first][nkazu.second] )
	  nkazu = now.kazu;
      }

      if( !vis[ntaka.first][ntaka.second][nkazu.first][nkazu.second] ){
	vis[ntaka.first][ntaka.second][nkazu.first][nkazu.second] = true;
      
	State next( ntaka, nkazu, now.time+1 );
	qs.push( next );
      }
    }
  }
  return -1;
}

int main()
{
  while(true){
    int H, W;
    
    cin >> H >> W;
    if( H == 0 && W == 0 ) break;
    bool m[MAX][MAX];
    int tx,ty;
    int kx,ky;  
    cin >> tx >> ty;
    cin >> kx >> ky;
    --tx;--ty;--kx;--ky;
    for(int i = 0; i < H; ++i){
      for(int j = 0; j < W; ++j){
	cin >> m[i][j];
      }
    }
    int ans = bfs( ty, tx, ky, kx, H, W, m);
    if( ans < 0 ){
      cout << "NA" << endl;
    }
    else{
      cout << ans << endl;
    }
  }
  return 0;
}

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

#define INF (1 << 25)

using namespace std;

vector<vector<vector<vector<int> > > > dp;

vector<vector<int> > M;

int H, W, sx1, sy1, sx2, sy2;

const int dx[4] = { 0, 1, 0, -1 };
const int dy[4] = { 1, 0, -1, 0 };

int bfs()
{
    dp = vector<vector<vector<vector<int> > > >(H, vector<vector<vector<int> > >(W, vector<vector<int> >(H, vector<int>(W, INF)))); dp[sy1][sx1][sy2][sx2] = 0;
    
    queue<pair<pair<pair<int, int>, pair<int, int> >, int> > que; que.push(make_pair(make_pair(make_pair(sx1, sy1), make_pair(sx2, sy2)), 0));
    
    while(!que.empty())
    {
        int x1 = que.front().first.first.first;
        int y1 = que.front().first.first.second;
        int x2 = que.front().first.second.first;
        int y2 = que.front().first.second.second;
        
        int turn = que.front().second;
        
        que.pop();
        
        for(int dir = 0; dir < 4; dir++)
        {
            int tx1 = x1 + dx[dir]; if(tx1 < 0 || tx1 > W) { tx1 -= dx[dir]; }
            int ty1 = y1 + dy[dir]; if(ty1 < 0 || ty1 > H) { ty1 -= dy[dir]; }
            int tx2 = x2 - dx[dir]; if(tx2 < 0 || tx2 > W) { tx2 += dx[dir]; }
            int ty2 = y2 - dy[dir]; if(ty2 < 0 || ty2 > H) { ty2 += dy[dir]; }
            
            if(M[ty1][tx1] == 1) { tx1 -= dx[dir]; ty1 -= dy[dir]; }
            if(M[ty2][tx2] == 1) { tx2 += dx[dir]; ty2 += dy[dir]; }
            
            if(tx1 == tx2 && ty1 == ty2) { return turn + 1; }
            
            if(dp[ty1][tx1][ty2][tx2] == INF)
            {
                dp[ty1][tx1][ty2][tx2] = turn + 1;
                
                que.push(make_pair(make_pair(make_pair(tx1, ty1), make_pair(tx2, ty2)), turn + 1));
            }
        }
    }
    
    return -1;
}

int main()
{
    while(true)
    {
        cin >> W >> H;
        
        if(H == 0 && W == 0) { break; }
        
        M = vector<vector<int> >(H, vector<int>(W));
        
        cin >> sx1 >> sy1 >> sx2 >> sy2;
        
        sx1--; sy1--; sx2--; sy2--;
        
        for(int i = 0; i < H; i++)
        {
            for(int j = 0; j < W; j++)
            {
                cin >> M[i][j];
            }
        }
        
        int Ans = bfs();
        
        if(Ans == -1)
        {
            cout << "NA" << endl;
        }
        else
        {
            cout << Ans << endl;
        }
    }
    
    return 0;
}