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 <stdio.h>
#include <queue>
using namespace std;

class adres{
public:
	int tkayuki[2],kazuyuki[2],cost;
	
	//adres型の比較
	bool chek(adres the){
		int c = 0;
		int i;
		for(i = 0; i < 2; i++){
			if(the.kazuyuki[i] == kazuyuki[i]){
				c++;
			}
			if(the.tkayuki[i] == tkayuki[i]){
				c++;
			}
		}
		return c == 4;
	}

	//孝幸と和幸の現在地が同じかどうか
	bool takazu(){
		return (tkayuki[1] == kazuyuki[1] && tkayuki[0] == kazuyuki[0]);
	}

	void print(){
		printf("T:%d,%d K:%d,%d C:%d\n",tkayuki[0],tkayuki[1],kazuyuki[0],kazuyuki[1],cost);
	}
};


void syokika();
void in();
void debag();
bool cheklast(adres);
void haba();

//変数宣言
int x,y;
int kx[4] = {1,-1,0,0},ky[4] = {0,0,-1,1},tkx[4] = {-1,1,0,0},tky[4] = {0,0,1,-1};
int i,j,r;
int anser;
bool anserchek;
int map[52][52];
adres start,now,nex;
queue<adres> que,laston;


int main()
{
	
	scanf("%d%d",&x,&y);
	
	while(x != 0 && y != 0){
		//初期化
		syokika();

		//入力
		in();

		//デバック用出力
		debag();

		//幅優先探索
		haba();
		
		scanf("%d%d",&x,&y);
	}

	return 0;
}
void syokika()
{
	int i;

	for(i = 0; i <= x+1; i++){
		map[i][0] = 1;
		map[i][y+1] = 1;
	}
	for(i = 0; i <= y+1; i++){
		map[0][i] = 1;
		map[x+1][i] = 1;
	}
	while(!que.empty()){
		que.pop();
	}
	while(!laston.empty()){
		laston.pop();
	}
	anserchek = false;
	anser = 0;
}
void in()
{
	int tx,ty;
	scanf("%d%d",&tx,&ty);
	start.tkayuki[0] = tx;
	start.tkayuki[1] = ty;
	scanf("%d%d",&tx,&ty);
	start.kazuyuki[0] = tx;
	start.kazuyuki[1] = ty;
	start.cost = 0;
	
	for(i = 1; i <= y; i++){
		for(j = 1; j <= x; j++){
			scanf("%d",&map[j][i]);
		}
	}
}
void debag()
{
	//マップ
	for(i = 0; i <= y+1; i++){
		for(j = 0; j <= x+1; j++){
			printf("%d",map[j][i]);
		}
		printf("\n");
	}
	/*各種関数
	now.kazuyuki[0] = 0;
		now.kazuyuki[1] = 0;
		now.tkayuki[0] = 0;
		now.tkayuki[1] = 1;
		nex = now;
		laston.push(now);
		for(i = 0; i < 10; i++){
			nex.kazuyuki[0]++;
			laston.push(nex);
		}
		now.print();
		printf("%d\n",cheklast(now));
	*/
}
bool cheklast(adres nex){
	int c = 0;
	while(laston.size() != c){
		//キューの中身と引数nexが一致していたら
		if( nex.chek(laston.front()) )	break;
		laston.push(laston.front());
		laston.pop();
		c++;
	}

	return (laston.size() != c);
}
void haba()
{
	que.push(start);
	while(!que.empty()){
		now = que.front();
		//now.print();
		que.pop();
		//ゴールかコストが100以上の場合
		if(now.takazu() || now.cost >= 100){
			break;
		}
		//移動処理
		now.cost++;
		for(i = 0; i < 4; i++){
			int nextky = now.kazuyuki[1] + ky[i];
			int nextkx = now.kazuyuki[0] + kx[i];
			int nexttky = now.tkayuki[1] + tky[i];
			int nexttkx = now.tkayuki[0] + tkx[i];
			int c = 0;
			nex = now;
			if(map[nextkx][nextky] == 0 || map[nexttkx][nexttky] == 0){
				if(map[nexttkx][nexttky] == 0){
					nex.tkayuki[0] = nexttkx;
					nex.tkayuki[1] = nexttky;
				}
				if(map[nextkx][nextky] == 0){
					nex.kazuyuki[0] = nextkx;
					nex.kazuyuki[1] = nextky;
				}
				//過去に行った場所でなければ
				if(!cheklast(nex)){
					que.push(nex);
					laston.push(nex);
				}
			}
		}
	}
	if(now.takazu())	printf("%d\n",now.cost);
	else				printf("NA\n");
}

C++: #include<iostream>
#include<queue>
using namespace std;
#define MAX 50
struct Data{int tx,ty,kx,ky,cost;};
int main()
{
  int X,Y,tx,ty,kx,ky,d[MAX][MAX];
  int i,j,x,y;
  int dx[4]={1,0,-1,0};
  int dy[4]={0,1,0,-1};
  queue<Data> q;
  bool f,visited[MAX][MAX][MAX][MAX];
  while(cin>>X>>Y>>tx>>ty>>kx>>ky,X|Y){
    for(j=0;j<Y;j++)for(i=0;i<X;i++)cin>>d[i][j];
    for(j=0;j<Y;j++)for(i=0;i<X;i++)for(y=0;y<Y;y++)for(x=0;x<X;x++)visited[i][j][x][y]=false;
    while(q.size())q.pop();
    tx--;ty--;kx--;ky--;
    Data p={tx,ty,kx,ky,0},pp;
    q.push(p);
    f=false;
    while(q.size()){
      p=q.front();
      q.pop();
      if(p.tx==p.kx&&p.ty==p.ky){f=true;break;}
      visited[p.tx][p.ty][p.kx][p.ky]=true;
      for(i=0;i<4;i++){
	pp=p;
	pp.tx+=dx[i];pp.ty+=dy[i];
	pp.kx+=dx[(i+2)%4];pp.ky+=dy[(i+2)%4];
	pp.cost++;
	if(pp.tx<0||X<=pp.tx||pp.ty<0||Y<=pp.ty||d[pp.tx][pp.ty]){pp.tx=p.tx;pp.ty=p.ty;}
	if(pp.kx<0||X<=pp.kx||pp.ky<0||Y<=pp.ky||d[pp.kx][pp.ky]){pp.kx=p.kx;pp.ky=p.ky;}
	if(visited[pp.tx][pp.ty][pp.kx][pp.ky])continue;
	visited[pp.tx][pp.ty][pp.kx][pp.ky]=true;
	q.push(pp);
      }
    }
    if(f)cout<<p.cost<<endl;
    else puts("NA");
  }
}

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

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

struct State { int tx, ty, kx, ky, cost; };
int X, Y;
int d[52][52];
bool used[52][52][52][52];

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	while (cin >> X >> Y, X) {
		int tx, ty, kx, ky;
		cin >> tx >> ty >> kx >> ky;
		for (int i=0; i<=Y+1; ++i) {
			for (int j=0; j<=X+1; ++j) {
				if (i==0 || i==Y+1 || j==0 || j==X+1) d[i][j] = 1;
				else cin >> d[i][j];
			}
		}
		memset(used, false, sizeof used);
		queue<State> q;
		q.push((State){tx, ty, kx, ky, 0});
		int res = -1;
		while ( ! q.empty()) {
			State s = q.front(); q.pop();
			if (used[s.tx][s.ty][s.kx][s.ky]) continue;
			used[s.tx][s.ty][s.kx][s.ky] = true;
			if (s.tx == s.kx && s.ty == s.ky) {
				res = s.cost;
				break;
			}
			for (int i=0; i<4; ++i) {
				if (d[s.ty+dy[i]][s.tx+dx[i]] && d[s.ky-dy[i]][s.kx-dx[i]]) continue;
				int tx2 = s.tx, ty2 = s.ty;
				if ( ! d[s.ty+dy[i]][s.tx+dx[i]]) {
					tx2 += dx[i];
					ty2 += dy[i];
				}
				int kx2 = s.kx, ky2 = s.ky;
				if ( ! d[s.ky-dy[i]][s.kx-dx[i]]) {
					kx2 -= dx[i];
					ky2 -= dy[i];
				}
				if ( ! used[tx2][ty2][kx2][ky2] && s.cost+1 < 100) {
					q.push((State){tx2, ty2, kx2, ky2, s.cost+1});
				}
			}
		}
		if (res < 0) {
			cout << "NA" << endl;
		} else {
			cout << res << endl;
		}
	}
	return 0;
}