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 (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)
	//pq.Push(start)
	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 pq.Len() > 0 {
		//now := heap.Pop(&pq).(*Status)
		//now := pq.Pop().(*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]
			}
			if now==next {
				continue
			}
			next.Turn += 1
			if next.Turn <= 100 {
				//heap.Push(&pq, next)
				//pq.Push(next)
				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>
#define M 52
#include<queue>
#include<cstring>
using namespace std;
struct P{
	int ax,ay,bx,by,cost;
	P(){}
	P(int h,int j,int k,int l,int co):
	ax(h),ay(j),bx(k),by(l),cost(co){}
};
int main(){
	bool s[M][M],d[M][M][M][M],u;
	int w,h,tx,ty,kx,ky,dx[]={1,-1,0,0},dy[]={0,0,-1,1};
	while(cin>>w>>h,w||h){
		cin>>tx>>ty;tx--;ty--;
		cin>>kx>>ky;kx--;ky--;
		for(int i=0;i<h;i++)
		for(int j=0;j<w;j++)
		cin>>s[i][j];
		queue<P> que;
		memset(d,sizeof(d),0);
		d[tx][ty][kx][ky]=1;
		que.push(P(tx,ty,kx,ky,0));
		u=true;
		while(!que.empty()){
			P p=que.front();
			que.pop();
			if(p.cost==100)
			break;
			if(p.ax==p.bx&&p.ay==p.by){
				cout<<p.cost<<endl;
				u=false;
				break;
			}
			int ntx,nty,nkx,nky;
			for(int i=0;i<4;i++){
				ntx=p.ax+dx[i];
				nty=p.ay+dy[i];
				nkx=p.bx-dx[i];
				nky=p.by-dy[i];
				if(!(ntx>=0&&ntx<w&&nty>=0&&nty<h)||s[nty][ntx]==1){
					ntx=p.ax;nty=p.ay;
				}
				if(!(nkx>=0&&nkx<w&&nky>=0&&nky<h)||s[nky][nkx]==1){
					nkx=p.bx;nky=p.by;
				}
				if(d[ntx][nty][nkx][nky]!=1)
				que.push(P(ntx,nty,nkx,nky,p.cost+1));
				d[ntx][nty][nkx][nky]=1;
			}
		}
		if(u)
		cout<<"NA"<<endl;
	}
	return 0;
}

C++: #include <iostream>
#include <queue>

using namespace std;

typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vvvi> vvvvi;

struct Point{
	int x,y;
	Point(){}
	Point(int x,int y):x(x),y(y){}
	bool operator==(const Point& p)const{return x==p.x && y==p.y;}
};

int main()
{
	for(int w,h;cin>>w>>h,w|h;){
		Point tak,kaz;
		cin>>tak.x>>tak.y>>kaz.x>>kaz.y;
		tak.x--; tak.y--;
		kaz.x--; kaz.y--;
		
		vvi grid(h,vi(w));
		for(int i=0;i<h;i++)
			for(int j=0;j<w;j++)
				cin>>grid[i][j];
		
		vvvvi vis(h,vvvi(w,vvi(h,vi(w,-1))));
		queue<pair<Point,Point>> q;
		vis[tak.y][tak.x][kaz.y][kaz.x]=0;
		q.emplace(tak,kaz);
		int res=-1;
		while(q.size()){
			tak=q.front().first;
			kaz=q.front().second;
			q.pop();
			
			if(vis[tak.y][tak.x][kaz.y][kaz.x]>=100)
				break;
			if(tak==kaz){
				res=vis[tak.y][tak.x][kaz.y][kaz.x];
				break;
			}
			
			int dx[]={-1,1,0,0},dy[]={0,0,-1,1};
			for(int k=0;k<4;k++){
				int tx=tak.x+dx[k],ty=tak.y+dy[k];
				int kx=kaz.x-dx[k],ky=kaz.y-dy[k];
				if(tx<0 || w<=tx || ty<0 || h<=ty || grid[ty][tx])
					tx=tak.x,ty=tak.y;
				if(kx<0 || w<=kx || ky<0 || h<=ky || grid[ky][kx])
					kx=kaz.x,ky=kaz.y;
				if(vis[ty][tx][ky][kx]!=-1)
					continue;
				vis[ty][tx][ky][kx]=vis[tak.y][tak.x][kaz.y][kaz.x]+1;
				q.emplace(Point(tx,ty),Point(kx,ky));
			}
		}
		
		if(res==-1)
			puts("NA");
		else
			printf("%d\n",res);
	}
	
	return 0;
}

C++: #include<cstdio>
#include<iostream>
#include<algorithm>
#include<math.h>
#include<queue>
#include<string.h>
#include<string>
#include<vector>
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));
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;
}