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);

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

        int tx,ty,kx,ky;

        scanf(" %d %d %d %d",&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<h;i++){
            for(int j=0;j<w;j++){
                scanf(" %d",&table[i][j]);
            }
        }

        //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;

        q.push(v);

        bool check = false;

        while(!q.empty()){

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

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

            if(v[0] >= w || v[1] >= h || v[2] >= w || v[3] >= h || v[0] < 0 || v[1] < 0 || v[2] < 0 || v[3] < 0 || table[v[0]][v[1]] == 1 || table[v[2]][v[3]] == 1){
                continue;
            }

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

            if(v[0] == v[2] && v[1] == v[3]){
                check = true;
                printf("%d\n",v[4]);
                break;
            }

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

            v[4]++;

            vector<int> before(5);

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

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

            q.push(v);

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

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

            q.push(v);

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

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

            q.push(v);

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

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

            q.push(v);

            /*if(v[0] >= w || v[1] >= h || v[2] >= w || v[3] >= h || v[0] < 0 || v[1] < 0 || v[2] < 0 || v[3] < 0 || table[v[0]][v[1]] == 1 || table[v[2]][v[3]] == 1){

            }else {
                q.push(v);
            }*/



        }

        if(!check){
            printf("NA\n");
        }



    }

    return 0;
}

C++: #include <iostream>
#include <queue>
#include <string.h>
using namespace std;
struct data{
    int x=0,y=0,turn=0;
};
data t,s;
queue <data> q,er;
int main(void){
    int w,h,tx,ty,kx,ky,d[51][51];
    cin>>w>>h;
    while(w!=0||h!=0){
        cin>>tx>>ty>>kx>>ky;
        t.x=tx;
        t.y=ty;
        t.turn=0;
        q.push(t);
        s.x=kx;
        s.y=ky;
        s.turn=0;
        er.push(s);
        for(int i=1;i<=h;i++){
            for(int p=1;p<=w;p++){
                cin>>d[i][p];
            }
        }
        int fx,ax,mx[]={0,1,0,-1},rx[]={0,-1,0,1};
        int fy,ay,my[]={1,0,-1,0},ry[]={-1,0,1,0};
        int te,se,cnt=0;
        while (1){
            cnt++;
            cout<<cnt<<' '<<t.turn<<endl;
            t=q.front();
            ty=t.y;
            tx=t.x;
            te=t.turn;
            s=er.front();
            ky=s.y;
            kx=s.x;
            se=s.turn;
            q.pop();
            er.pop();/*
            for(int i=1;i<=h;i++){
                for(int p=1;p<=w;p++){
                    if(i==t.y&&p==t.x){
                        cout<<"t ";
                    }
                    else if(i==s.y&&p==s.x){
                        cout<<"s ";
                    }
                    else{
                        cout<<d[i][p]<<' ';
                    }
                }
                cout<<endl;
            }
            cout<<endl<<endl;*/
            if(t.y==s.y&&t.x==s.x){
                cout<<t.turn<<endl;
                break;
            }
            if(t.turn>=100){
                cout<<"NA"<<endl;
                break;
            }
            for(int i=0;i<4;i++){
                fx=tx+mx[i];
                fy=ty+my[i];
                ax=kx+rx[i];
                ay=ky+ry[i];
                if(d[fy][fx]==0&&ax>0&&ax<=w&&ay>0&&ay<=h){
                    t.y=fy;
                    t.x=fx;
                    t.turn=te+1;
                    q.push(t);
                }
                else if(d[fy][fx]==1||fx<=0||fx>w||fy<=0||fy>h){
                    t.turn=te+1;
                    q.push(t);
                }
                if(d[ay][ax]==0&&ax>0&&ax<=w&&ay>0&&ay<=h){
                    s.y=ay;
                    s.x=ax;
                    s.turn=se+1;
                    er.push(s);
                }
                else if(d[ay][ax]==1||ax<=0||ax>w||ay<=0||ay>h){
                    s.turn=se+1;
                    er.push(s);
                }
            }
        }
        while(!q.empty()){
            q.pop();
        }
        while(!er.empty()){
            er.pop();
        }
        cnt=0;
        memset(d,0,sizeof(d));
        cin>>w>>h;
    }
}