Go: package main

import (
	"container/heap"
	"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)
	dx := []int64{0, 1, 0, -1}
	dy := []int64{1, 0, -1, 0}
	memo := make(map[PersonPosition]struct{}, 0)
	for pq.Len() > 0 {
		now := heap.Pop(&pq).(*Status)
		if now.Person.Distance() == 0 {
			fmt.Println(now.Turn)
			return
		}
		if _, ok := memo[now.Person]; ok {
			continue
		}
		memo[now.Person] = struct{}{}
		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 += 1
			if next.Turn < 100 {
				heap.Push(&pq, next)
			}
		}
	}
	fmt.Println("NA")
}

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

C++: #include <queue>
#include <vector>
#include <cstring>
#include <iostream>
using namespace std;
int H, W, ax, ay, bx, by, x[52][52], dp[52][52][52][52];
int dx[4] = {0, 1, 0, -1}, dy[4] = {1, 0, -1, 0};
int main() {
	while(cin >> W >> H >> ax >> ay >> bx >> by) {
		for(int i = 0; i < H + 2; i++) {
			for(int j = 0; j < W + 2; j++) {
				x[i][j] = 1;
				if(i && i != H + 1 && j && j != W + 1) scanf("%d", &x[i][j]);
			}
		}
		memset(dp, -1, sizeof(dp)); dp[ay][ax][by][bx] = 0;
		queue<vector<int> > que; que.push({ax, ay, bx, by});
		bool flag = false;
		while(!que.empty()) {
			vector<int> v1 = que.front(); que.pop();
			for(int i = 0; i < 4; i++) {
				vector<int> v2 = v1;
				if(!x[v1[1] + dy[i]][v1[0] + dx[i]]) v2[0] += dx[i], v2[1] += dy[i];
				if(!x[v1[3] - dy[i]][v1[2] - dx[i]]) v2[2] -= dx[i], v2[3] -= dy[i];
				if(v2[0] == v2[2] && v2[1] == v2[3]) {
					flag = true; break;
				}
				if(dp[v2[1]][v2[0]][v2[3]][v2[2]] == -1) {
					dp[v2[1]][v2[0]][v2[3]][v2[2]] = dp[v1[1]][v1[0]][v1[3]][v1[2]] + 1;
					que.push(v2);
				}
			}
			if(flag) {
				cout << dp[v1[1]][v1[0]][v1[3]][v1[2]] + 1 << endl; break;
			}
		}
		if(!flag) cout << "NA" << endl;
	}
}

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,-1,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];
}
}
while (!que.empty())
{
c = que.front();
que.pop();
java[c.tx][c.ty][c.kx][c.ky] = 1;
if (c.tx == c.kx&&c.ty == c.ky||c.t >= 100)
{
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]] != 0 && 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]] != 0)
{
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;
}