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;

int table[51][51];

bool memo[51][51][51][51];

int main() {

    while(1){

        int w,h;

        //scanf(" %d %d",&w,&h);

        cin >> w >> h;

        if(w==0&&h==0) break;

        int tx,ty,kx,ky;

        //scanf(" %d %d %d %d",&tx,&ty,&kx,&ky);

        cin >> tx >> ty >> kx >> ky;

        tx--;ty--;kx--;ky--;

        for(int i=0;i<51;i++){
            for(int j=0;j<51;j++){
                table[i][j] = 1;
                for(int k=0;k<51;k++){
                    for(int r=0;r<51;r++){
                        memo[i][j][k][r] = false;
                    }
                }
            }
        }

        for(int i=0;i<w;i++){
            for(int j=0;j<h;j++){
                //scanf(" %d",&table[i][j]);
                cin >> table[i][j];
                if(table[i][j] == 1){
                    for(int k=0;k<51;k++){
                        for(int r=0;r<51;r++){
                            memo[i][j][k][r] = true;
                        }
                    }
                }
            }
        }

        /*printf("\n");

        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                printf("%d ",table[i][j]);
            }
            printf("\n");
        }*/

        //memset(memo,false,sizeof(memo));

        queue<vector<int> > q;

        vector<int> v(5);

        v[0] = tx; v[1] = ty; v[2] = kx; v[3] = ky; v[4] = 0;

        if(table[v[0]][v[1]] == 1 || table[v[2]][v[3]] == 1){
            cout << "NA" << endl;
            continue;
        }

        q.push(v);

        bool check = false;

        while(!q.empty()){

            v = q.front(); q.pop();

            if(memo[v[0]][v[1]][v[2]][v[3]]){
                continue;
            }

            if(v[0] == v[2] && v[1] == v[3]){
                check = true;
                cout << v[4] << endl;
                break;
            }

            memo[v[0]][v[1]][v[2]][v[3]] = true;

            v[4]++;

            if(v[4] >= 100){
                break;
            }

            vector<int> before(5);

            for(int i=0;i<5;i++){
                before[i] = v[i];
            }

            v[0]--; v[2]++;

            if(v[0] == -1 || table[v[0]][v[1]] == 1){
                v[0]++;
            }
            if(v[2] == w || table[v[2]][v[3]] == 1){
                v[2]--;
            }

            q.push(v);

            for(int i=0;i<5;i++){
                v[i] = before[i];
            }

            v[0]++; v[2]--;

            if(v[2] == -1 || table[v[2]][v[3]] == 1){
                v[2]++;
            }
            if(v[0] == w || table[v[0]][v[1]] == 1){
                v[0]--;
            }

            q.push(v);


            for(int i=0;i<5;i++){
                v[i] = before[i];
            }

            v[1]++; v[3]--;

            if(v[3] == -1 || table[v[2]][v[3]] == 1){
                v[3]++;
            }
            if(v[1] == h || table[v[0]][v[1]] == 1){
                v[1]--;
            }

            q.push(v);

            for(int i=0;i<5;i++){
                v[i] = before[i];
            }

            v[1]--; v[3]++;

            if(v[1] == -1 || table[v[0]][v[1]] == 1){
                v[1]++;
            }
            if(v[3] == h || table[v[2]][v[3]] == 1){
                v[3]--;
            }

             q.push(v);
        }

        if(!check){
            cout << "NA" << endl;
        }



    }

    return 0;
}

C++: #include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<map>
#include<set>
#include<utility>
#include<cmath>
#include<cstring>
#include<queue>
#include<cstdio>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define pb push_back
#define mp make_pair
#define all(in) in.begin(),in.end()
const double PI=acos(-1);
const double EPS=1e-10;
const int inf=1e9;
using namespace std;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pii;
int dx[]={0,1,0,-1};
int dy[]={1,0,-1,0};
int h[60][60][60][60];
int main(){
	int n,m;
	while(cin>>m>>n,n||m){
		rep(i,60)rep(j,60)rep(k,60)rep(l,60)h[i][j][k][l]=false;
		int sx,sy,gx,gy;
		cin>>sy>>sx>>gy>>gx;
		vvi in(n+2,vi(m+2,1));
		rep(i,n)rep(j,m)cin>>in[i+1][j+1];
		queue<pair<pii,pii> >q;
		q.push(pair<pii,pii>(pii(sx,sy),pii(gx,gy)));
		h[sx][sy][gx][gy]=true;
		int out=0;
		while(1){
			out++;
			queue<pair<pii,pii> >nex;
			while(q.size()){
				pair<pii,pii>now=q.front();q.pop();
				pii ta=now.first,ka=now.second;
				rep(i,4){
					int tx=ta.first+dx[i],ty=ta.second+dy[i];
					int kx=ka.first+dx[(i+2)%4],ky=ka.second+dy[(i+2)%4];
					if(in[tx][ty]==1){
						tx-=dx[i];ty-=dy[i];
					}
					if(in[kx][ky]==1){
						kx-=dx[(i+2)%4];ky-=dy[(i+2)%4];
					}
					if(kx==tx&&ky==ty)goto end;
					if(h[tx][ty][kx][ky])continue;
					h[tx][ty][kx][ky]=true;
					nex.push(pair<pii,pii>(pii(tx,ty),pii(kx,ky)));
				}
			}
			q=nex;
			if(q.size()==0){
				cout<<"NA"<<endl;
				goto br;
			}
		}
		end:;
		cout<<out<<endl;
		br:;
	}
}