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 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 <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;

const int INF = 1 << 30;
int dy[] = {-1, 0, 1, 0};
int dx[] = {0, -1, 0, 1};
int W, H;
int tx, ty;
int kx, ky;
int d[50][50];
int dist[50][50][50][50];

int main() {
  cin.tie(0);
  ios_base::sync_with_stdio(false);
  cout << fixed << setprecision(10);
  
  while (cin >> W >> H, W) {
    cin >> tx >> ty >> kx >> ky;
    tx--, ty--, kx--, ky--;
    for (int i = 0; i < H; i++) {
      for (int j = 0; j < W; j++) {
        cin >> d[i][j];
      }
    }
    fill_n((int*)dist, 50 * 50 * 50 * 50, INF);
    dist[ty][tx][ky][kx] = 0;
    using P = tuple<int, int, int, int>;
    queue<P> que;
    que.emplace(ty, tx, ky, kx);
    bool na = true;
    while (!que.empty()) {
      int ay, ax, by, bx;
      tie(ay, ax, by, bx) = que.front(); que.pop();
      if (dist[ay][ax][by][bx] >= 100) break;
      if (pii(ay, ax) == pii(by, bx)) {
        cout << dist[ay][ax][by][bx] << endl;
        na = false;
        break;
      }
      for (int i = 0; i < 4; i++) {
        int any = ay + dy[i];
        int anx = ax + dx[i];
        int bny = by + dy[(i + 2) % 4];
        int bnx = bx + dx[(i + 2) % 4];
        if (any < 0 || any >= H || anx < 0 || anx >= W || d[any][anx]) any = ay, anx = ax;
        if (bny < 0 || bny >= H || bnx < 0 || bnx >= W || d[bny][bnx]) bny = by, bnx = bx;
        if (dist[any][anx][bny][bnx] > dist[ay][ax][by][bx] + 1) {
          dist[any][anx][bny][bnx] = dist[ay][ax][by][bx] + 1;
          que.emplace(any, anx, bny, bnx);
        }
      }
    }
    if (na) cout << "NA" << endl;
  }  

  return 0;
}

C++: #include<iostream>
#include<queue>
#include<string.h>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
struct X
{
int tx, ty, t, kx, ky;
};
int java[51][51][51][51] = { 0 };
int main()
{
int w, h, map[52][52] = { 0 };
int mx[4] = { 0,1,0,-1 }, my[4] = { 1,0,-1,0 };
while (1)
{
queue<X> que;
X c;
cin >> w >> h;
if (w == 0 && h == 0)
break;
memset(java, 0, sizeof(java));
memset(map,0,sizeof(map));
cin >> c.tx >> c.ty >> c.kx >> c.ky;
c.t = 0;
que.push(c);
rep1(i, h)
{
rep1(j, w)
{
cin >> map[i][j];
}
}
for(int i=0;i<=h+1;i++)
{
map[i][0] = 1;
map[i][w + 1] = 1;
}
for(int i=0;i<=w+1;i++)
{
map[0][i] = 1;
map[h + 1][i] = 1;
}
while (!que.empty())
{
c = que.front();
que.pop();
cout<<"T "<<map[c.tx][c.ty]<<' '<<c.tx<<' '<<c.ty<<"K "<<map[c.kx][c.ky]<<' '<<c.kx<<' '<<c.ky<<endl;
java[c.tx][c.ty][c.kx][c.ky] = 1;
if (c.tx == c.kx&&c.ty == c.ky||c.t >= 100)
{
cout << "FACKYOU!" << endl;
break;
}
c.t++;
rep(i, 4)
{
if (java[c.tx + mx[i]][c.ty + my[i]][c.kx - mx[i]][c.ky - my[i]] == 0 && map[c.tx + mx[i]][c.ty + my[i]] == 0 && map[c.kx - mx[i]][c.ky - my[i]] == 0)
{
c.tx += mx[i];
c.ty += my[i];
c.kx -= mx[i];
c.ky -= my[i];
que.push(c);
java[c.tx][c.ty][c.kx][c.ky] = 1;
c.tx -= mx[i];
c.ty -= my[i];
c.kx += mx[i];
c.ky += my[i];
}
else if (java[c.tx][c.ty][c.kx - mx[i]][c.ky - my[i]] == 0 && map[c.tx + mx[i]][c.ty + my[i]] == 1 && map[c.kx - mx[i]][c.ky - my[i]] == 0)
{
c.kx -= mx[i];
c.ky -= my[i];
que.push(c);
java[c.tx][c.ty][c.kx][c.ky] = 1;
c.kx += mx[i];
c.ky += my[i];
}
else if (java[c.tx + mx[i]][c.ty + my[i]][c.kx][c.ky] == 0 && map[c.tx + mx[i]][c.ty + my[i]] == 0 && map[c.kx - mx[i]][c.ky - my[i]] == 1)
{
c.tx += mx[i];
c.ty += my[i];
que.push(c);
java[c.tx][c.ty][c.kx][c.ky] = 1;
c.tx -= mx[i];
c.ty -= my[i];
}
}
}
if (c.tx==c.kx&&c.ky==c.ty)
cout << c.t << endl;
else
cout << "NA" << endl;
}
return 0;
}

C++: #include<iostream>
#include<utility>
#include<queue>
using namespace std;
int dx[4] = { 1,0,-1,0 };
int dy[4] = { 0,1,0,-1 };
int main() {
	int W, H, tx, ty, kx, ky;
	bool d[52][52];
	bool memo[52][52][52][52];
	while (true) {
		cin >> W >> H;
		if (W == 0)break;
		for (int i = 0; i < 52; i++) {
			for (int j = 0; j < 52; j++) {
				for (int k = 0; k < 52; k++) {
					for (int l = 0; l < 52; l++) {
						memo[i][j][k][l] = false;
					}
				}
			}
		}
		for (int i = 0; i < 52; i++) {
			for (int j = 0; j < 52; j++) {
				d[i][j] = 1;
			}
		}
		cin >> tx >> ty >> kx >> ky;
		for (int i = 1; i < H + 1; i++) {
			for (int j = 1; j < W + 1; j++) {
				cin >> d[j][i];
			}
		}
		pair<pair<int, int>, pair<int, int> >num;
		num.first.first = tx;
		num.first.second = ty;
		num.second.first = kx;
		num.second.second = ky;
		queue<pair<pair<int, int>, pair<int, int> > > q;
		q.push(num);
		int qsize = 1;
		int loopcount = 0;
		while (!q.empty()) {
			num = q.front();
			q.pop();
			if (qsize == 0) {
				qsize = q.size();
				loopcount++;
				if (loopcount == 100 || qsize==0) {
					cout << "NA" << endl;
					break;
				}
			}
			qsize--;
			if (memo[num.first.first][num.first.second][num.second.first][num.second.second]) {
				continue;
			}
			else {
				memo[num.first.first][num.first.second][num.second.first][num.second.second] = true;
			}
			if (num.first.first == num.second.first && num.first.second == num.second.second) {
				cout << loopcount << endl;
				break;
			}
			for (int i = 0; i < 4; i++) {
				pair<pair<int, int>, pair<int, int> >copy;
				copy = num;
				copy.first.first += dx[i];
				copy.first.second += dy[i];
				if (d[copy.first.first][copy.first.second]) {
					copy.first.first -= dx[i];
					copy.first.second -= dy[i];
				}
				copy.second.first -=dx[i];
				copy.second.second -= dy[i];
				if (d[copy.second.first][copy.second.second]) {
					copy.second.first += dx[i];
					copy.second.second += dy[i];
				}
				q.push(copy);
			}
		}
	}
	return 0;
}