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 := &Status{}
		now = pq[0]
		pq = pq[1:]
		if ans <= now.Turn {
			continue
		}
		if _, ok := memo[now.Person]; ok {
			continue
		}
		memo[now.Person] = now.Turn

		if now.Person.Distance() == 0 && ans > now.Turn {
			ans = 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 <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <ctime>
#include <cassert>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <functional>
#include <iostream>
#include <map>
#include <set>
using namespace std;
typedef pair<int,int> P;
typedef pair<int,P> P1;
typedef pair<P,P> P2;
typedef long long ll;
#define pu push
#define pb push_back
#define mp make_pair
#define eps 1e-7
#define INF 1000000000
#define fi first
#define sc second
#define rep(i,x) for(int i=0;i<x;i++)
int dp[55][55][55][55];
bool u[55][55][55][55];
int main()
{
	while(1)
	{
		int x,y;
		int ax,ay;
		int bx,by;
		cin >> x >> y; if(x == 0) return 0;
		cin >> ax >> ay;
		cin >> bx >> by; 
		int f[55][55];
		for(int i=0;i<y;i++)
		{
			for(int j=0;j<x;j++)
			{
				cin >> f[i][j];
			}
		}
		for(int i=0;i<55;i++) for(int j=0;j<55;j++) for(int k=0;k<55;k++) for(int l=0;l<55;l++) dp[i][j][k][l] = INF,u[i][j][k][l] = 0;
		dp[ay][ax][by][bx] = 0;
		queue<P2>que;
		que.push(mp(mp(ay,ax),mp(by,bx)));
		while(!que.empty())
		{
			P2 p = que.front(); que.pop();
			if(u[p.fi.fi][p.fi.sc][p.sc.fi][p.sc.sc]) continue;
			u[p.fi.fi][p.fi.sc][p.sc.fi][p.sc.sc] = true;
			int dx[4]={0,1,0,-1};
			int dy[4]={1,0,-1,0};
			for(int k=0;k<4;k++)
			{
				int ny = p.fi.fi+dy[k];
				int nx = p.fi.sc+dx[k];
				if(0<=ny && ny<y && 0<=nx && nx<x && f[ny][nx]==0)
				{
				}
				else
				{
					ny = p.fi.fi;
					nx = p.fi.sc;
				}
				int ny2 = p.sc.fi+dy[(k+2)%4];
				int nx2 = p.sc.sc+dx[(k+2)%4];
				if(0<=ny2 && ny2<y && 0<=nx2 && nx2<x && f[ny2][nx2]==0)
				{
				}
				else
				{
					ny2 = p.sc.fi;
					nx2 = p.sc.sc;
				}
				if(dp[ny][nx][ny2][nx2] > dp[p.fi.fi][p.fi.sc][p.sc.fi][p.sc.sc]+1)
				{
					dp[ny][nx][ny2][nx2] = dp[p.fi.fi][p.fi.sc][p.sc.fi][p.sc.sc]+1;
					que.push(mp(mp(ny,nx),mp(ny2,nx2)));
				}
			}
		}
		int res = INF;
		for(int i=0;i<y;i++) for(int j=0;j<x;j++) res = min(res,dp[i][j][i][j]);
		if(res >= 100) puts("NA");
		else printf("%d\n",res);
	}
}

C++: #include <iostream>
#include <queue>
using namespace std;
int H,W;
class Point{
public:
  int tx; //タカユキの座標
  int ty;
  int kx; //カズユキの座標
  int ky;
  int d; //ターン回数
  void set(int a,int b,int c,int d){
    tx = a;
    ty = b;
    kx = c;
    ky = d;
  }
};
int is_out_of_area(int y,int x) //座標が範囲内か確認する関数
{
  return x < 1 || x > W || y < 1 || y > H;
}
int main(){

  while(1){
    bool F[52][52]; //障害物
    bool D[52][52][52][52]; //探索済みかの判定用
    Point p,q;
    int tx,ty,kx,ky;
    queue<Point> qa;
    cin >> W >> H;
    if(W == 0 && H == 0)
    break;
    cin >> tx >> ty >> kx >> ky;
    for(int y=0;y<=H+1;y++){
      for(int x=0;x<=W+1;x++){
        F[y][x] = 1;
      }
    }
    for(int y=1;y<=H;y++){
      for(int x=1;x<=W;x++){
        int a;
        cin >> a;
        F[y][x] = a;
        for(int i=1;i<=H;i++){
          for(int j=1;j<=W;j++){
            D[y][x][i][j] = 1; //1:未探索 , 0:探索済み
          }
        }
      }
    }
    p.set(tx,ty,kx,ky);
    D[ty][tx][ky][kx] = 0;
    p.d = 0;
    qa.push(p);
    while(1){
      int inc_tx,inc_ty,inc_kx,inc_ky;
      if(qa.empty()){
        cout << "NA" <<endl;
        break;
      }
      p = qa.front();
      qa.pop();
      if(p.d >= 100){
        cout << "NA" << endl;
        break;
      }
      if(p.tx == p.kx && p.ty == p.ky){
        cout << p.d << endl;
        break;
      }

      if(D[p.ty-1][p.tx][p.ky+1][p.kx]){ //タカユキの y 座標を-1, カズユキを+1 同様の if 文が下に四つ続く

        inc_ty = -1 ; inc_ky = 1;
        if(is_out_of_area(p.ty-1,p.tx) || F[p.ty-1][p.tx]){ //範囲外または障害物にあたったならば移動しない
          inc_ty = 0;
        }
        if(is_out_of_area(p.ky+1,p.kx) || F[p.ky+1][p.kx]){ //範囲外または障害物にあたったならば移動しない
          inc_ky = 0;
        }
        if(inc_ty || inc_ky){ //どちらかが動ける状態であったならキューにプッシュ
          q.set(p.tx,p.ty + inc_ty,p.kx,p.ky+inc_ky);
          q.d = p.d + 1;
          qa.push(q);
          D[q.ty][q.tx][q.ky][q.kx] = 0;
        }

      }

      if(D[p.ty+1][p.tx][p.ky-1][p.kx]){
        inc_ty = 1 ; inc_ky = -1;
        if(is_out_of_area(p.ty+1,p.tx) || F[p.ty+1][p.tx]){inc_ty = 0;
        }
        if(is_out_of_area(p.ky-1,p.kx) || F[p.ky-1][p.kx]){
          inc_ky = 0;
        }
        if(inc_ty || inc_ky){
          q.set(p.tx,p.ty + inc_ty,p.kx,p.ky+inc_ky);
          q.d = p.d + 1;
          qa.push(q);
          D[q.ty][q.tx][q.ky][q.kx] = 0;
        }
      }

      if(D[p.ty][p.tx-1][p.ky][p.kx+1]){
        inc_tx = 1 ; inc_kx = 1;
        if(is_out_of_area(p.ty,p.tx + inc_tx) || F[p.ty][p.tx + inc_tx]){
          inc_tx = 0;
        }
        if(is_out_of_area(p.ky,p.kx + inc_kx) || F[p.ky][p.kx + inc_kx]){
          inc_kx = 0;
        }
        if(inc_tx || inc_kx){
          q.set(p.tx + inc_tx,p.ty,p.kx + inc_kx,p.ky);
          q.d = p.d + 1;
          qa.push(q);
          D[q.ty][q.tx][q.ky][q.kx] = 0;
        }
      }
      if(D[p.ty][p.tx+1][p.ky][p.kx-1]){
        inc_tx = 1 ; inc_kx = -1;
        if(is_out_of_area(p.ty,p.tx + inc_tx) || F[p.ty][p.tx + inc_tx]){
          inc_tx = 0;
        }
        if(is_out_of_area(p.ky,p.kx + inc_kx) || F[p.ky][p.kx + inc_kx]){
          inc_kx = 0;
        }
        if(inc_tx || inc_kx){
          q.set(p.tx + inc_tx,p.ty,p.kx + inc_kx,p.ky);
          q.d = p.d + 1;
          qa.push(q);
          D[q.ty][q.tx][q.ky][q.kx] = 0;
        }
      }

    }
    while(!qa.empty()){
      qa.pop();
    } //キューの残りカスを消去
  }
  return 0;
}