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 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)
	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 len(pq) > 0 {
		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 {
				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>
#include<cstdio>
#include<cstring>

using namespace std;

#define MAX 51

int xy[MAX][MAX];
int cost[MAX][MAX][MAX][MAX];
int X,Y;

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

struct state{
  int tx;
  int ty;
  int kx;
  int ky;
  int co;
  state(){}
  state(int tx,int ty,int kx,int ky,int co):
    tx(tx),ty(ty),kx(kx),ky(ky),co(co){}
};

int solve(int tx,int ty,int kx,int ky){

  memset(cost,101,sizeof(cost));

  queue<state> q;
  q.push( state(tx,ty,kx,ky,0) );

  while( !q.empty() ){
    state p=q.front();
    q.pop();

    tx=p.tx;
    ty=p.ty;
    kx=p.kx;
    ky=p.ky;

    cost[tx][ty][kx][ky]=p.co;

    for(int i=0;i<4;i++){

      int f=0;
      
      if(p.co+1>=100) continue;
      
      if(kx+dx[i]*-1 <= 0 || ky+dy[i]*-1 <=0 || kx+dx[i]*-1 > X || ky+dy[i]*-1 > Y)
	f+=10;      
      if(tx+dx[i] <= 0 || ty+dy[i] <= 0 || tx+dx[i] > X || ty+dy[i] > Y )
	f++;

      if( xy[ty+dy[i]][tx+dx[i]]==1 )
	f++;
      if(xy[ky+dy[i]*-1][kx+dx[i]*-1]==1 )
	f+=10;

      if(f/10>0 && f%10>0)
	continue;


      if(f==0){
	if(tx+dx[i] == kx+dx[i]*-1 && ty+dy[i] == ky+dy[i]*-1)
	  return p.co+1;
	if( cost[tx+dx[i]][ty+dy[i]][kx+dx[i]*-1][ky+dy[i]*-1] <= p.co)
	  continue;
	q.push( state(tx+dx[i],ty+dy[i],kx+dx[i]*-1,ky+dy[i]*-1,p.co+1) );
      }
      else if(f%10>0){
	if(tx == kx+dx[i]*-1 && ty == ky+dy[i]*-1)
	  return p.co+1;
	if( cost[tx][ty][kx+dx[i]*-1][ky+dy[i]*-1] <= p.co)
	  continue;
	q.push( state(tx,ty,kx+dx[i]*-1,ky+dy[i]*-1,p.co+1) );
      }
      else if(f/10>0){
	if(tx+dx[i] == kx && ty+dy[i] == ky)
	  return p.co+1;
	if( cost[tx+dx[i]][ty+dy[i]][kx][ky] <= p.co)
	  continue;
	q.push( state(tx+dx[i],ty+dy[i],kx,ky,p.co+1) );
      }
    }
  }
  return -1;
} 

main(){
  
  int i,j;
  int kx,ky,tx,ty;
  int n;

  while(1){
    
    cin >> X >> Y;

    if(X==0 && Y==0) break;
    
    cin >> tx >> ty;
    cin >> kx >> ky;
    
    for(i=1;i<=Y;i++){
      for(j=1;j<=X;j++){
	cin >> xy[i][j];
      }
    }
    
    n=solve(tx,ty,kx,ky);
    
    if(n==-1)
      cout << "NA" << endl;
    else
      cout << n << endl;
  }
  return 0;
}

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

struct state{ int lx,ly,rx,ry; };

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

int main(){
	int h,w;
	while(cin >> w >> h,w){
		int ax,ay,bx,by,mi = 101;
		bool used[50][50][50][50] = {},field[50][50];
		cin >> ay >> ax >> by >> bx; ax--;ay--;bx--;by--;
		for(int i = 0;i < h;i++){
			for(int j = 0;j < w;j++) cin >> field[i][j];
		}
		queue<state> que;
		que.push({ax,ay,bx,by});
		used[ax][ay][bx][by] = true;
		for(int i = 0;i < 100;i++){
			int siz = que.size();
			if(!siz) break;
			for(int j = 0;j < siz;j++){
				state s = que.front();que.pop();
				if(s.lx == s.rx && s.ly == s.ry) mi = min(i,mi);
				for(int k = 0;k < 4;k++){
					int nlx = s.lx + dx[k],nly = s.ly + dy[k],nrx = s.rx + dx[(k + 2) % 4],nry = s.ry + dy[(k + 2) % 4];
					bool move = false;
					if(nlx >= 0 && nlx < h && nly >= 0 && nly < w && !field[nlx][nly]) move = true;
					else{
						nlx = s.lx;
						nly = s.ly;
					}
					if(nrx >= 0 && nrx < h && nry >= 0 && nry < w && !field[nrx][nry]) move = true;
					else{
						nrx = s.rx;
						nry = s.ry;
					}
					if(move && !used[nlx][nly][nrx][nry]){
						used[nlx][nly][nrx][nry] = true;
						que.push({nlx,nly,nrx,nry});
					}
				}
			}
		}
		if(mi == 101) cout << "NA" << endl;
		else cout << mi << endl;
	}
	return 0;
}

C++: #include<iostream>
#include<string>
#include<vector>
#include<queue>
#define p pair<int,int>
#define P pair<p,p>
using namespace std;

int a[50][50][50][50];
int x[4] = { -1,0,0,1 }, y[4] = { 0,-1,1,0 };
int S[50][50];
signed main() {
	int b, c;
	while (cin >> c >> b, b | c) {
		memset(a, 0x3f, sizeof(a));
		int d, e, f, g; cin >> e >> d >> g >> f; d--; e--; f--; g--;
		a[d][e][f][g] = 0;
		for (int i = 0; i < b; i++) {
			for (int j = 0; j < c; j++) {
				scanf("%d", &S[i][j]);
			}
		}
		queue<P>Q;
		Q.push(P(p(d,e),p(f,g)));
		while (Q.size()) {
			P t = Q.front(); Q.pop();
			if (a[t.first.first][t.first.second][t.second.first][t.second.second] >= 100)break;
			if (t.first.first == t.second.first&&t.first.second == t.second.second) {
				cout << a[t.first.first][t.first.second][t.second.first][t.second.second] << endl;
				goto l;
		}
			for (int i = 0; i < 4; i++) {
				int j = 3 - i;
				p n, m; n = t.first; m = t.second;
				n.first += x[i]; n.second += y[i];
				m.first += x[j]; m.second += y[j];
				if (n.first < 0 || n.first >= b || n.second < 0 || n.second >= c||S[n.first][n.second]==1) {
					n.first -= x[i]; n.second -= y[i];
				}
				if (m.first < 0 || m.first >= b || m.second < 0 || m.second >= c||S[m.first][m.second]==1) {
					m.first -= x[j]; m.second -= y[j];
				}
				if (a[n.first][n.second][m.first][m.second] == 1061109567) {
					a[n.first][n.second][m.first][m.second] = a[t.first.first][t.first.second][t.second.first][t.second.second]+1;
					Q.push(P(p(n.first,n.second),p(m.first,m.second)));
				}
			}
		}
		puts("NA");
	l:;
	}
}