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)
	dx := []int64{0, 1, 0, -1}
	dy := []int64{1, 0, -1, 0}
	memo := make(map[PersonPosition]int64, 0)
	ans := int64(101)
	for pq.Len() > 0 {
		//now := heap.Pop(&pq).(*Status)
		now := pq.Pop().(*Status)
		if now.Person.Distance() == 0 && ans > now.Turn {
			ans = now.Turn
		}
		if v, ok := memo[now.Person]; ok && v <= now.Turn {
			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 += 1
			if next.Turn < 100 {
				//heap.Push(&pq, next)
				pq.Push(next)
			}
		}
	}
	if ans == 101 {
		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 dx[] = {1, -1, 0, 0};
int dy[] = {0, 0, 1, -1};

int memo[60][60][60][60] = {};

int mas[60][60];

typedef struct{
    int cost;
    int tx;
    int ty;
    int kx;
    int ky;
} Data;

Data make_data(int c, int x, int y, int xx, int yy){
    Data d;
    d.cost = c;
    d.ty = y;
    d.tx = x;
    d.ky = yy;
    d.kx = xx;
    return d;
}

int w, h;

bool isMove(int x, int y){
    return 0 <= x && x < w && 0 <= y && y < h && mas[y][x] == 0;
}

int main(){

    while(cin >> w >> h, w != 0 && h != 0){
        int tx, ty;
        int kx, ky;
        cin >> tx >> ty;
        cin >> kx >> ky;

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

        for(int i = 0;i < h;i++){
            for(int j = 0;j < w;j++){
                cin >> mas[i][j];
            }
        }

        memset(memo, -1, sizeof(memo));

        queue<Data> que;
        que.push(make_data(0, tx, ty, kx, ky));
        while(!que.empty()){
            int cost = que.front().cost;
            tx = que.front().tx;
            ty = que.front().ty;
            kx = que.front().kx;
            ky = que.front().ky;

            que.pop();

            if(cost >= 100){
                continue;
            }

            if(memo[tx][ty][kx][ky] != -1){
                continue;
            }

            memo[tx][ty][kx][ky] = cost;

            cost++;
            for(int i = 0;i < 4;i++){
                int nx = tx + dx[i];
                int ny = ty + dy[i];

                if(!isMove(nx, ny)){
                    nx -= dx[i];
                    ny -= dy[i];
                }

                int mx = kx - dx[i];
                int my = ky - dy[i];

                if(!isMove(mx, my)){
                    mx += dx[i];
                    my += dy[i];
                }

                que.push(make_data(cost, nx, ny, mx, my));
            }

        }

        int ans = INT_MAX;;
        for(int i = 0;i < h;i++){
            for(int j = 0;j < w;j++){
                if(memo[j][i][j][i] != -1){
                    ans = min(ans, memo[j][i][j][i]);
                }
            }
        }

        if(ans == INT_MAX){
            cout << "NA" << endl;
        }else{
            cout << ans << endl;
        }
    }
}

C++: #include<iostream>
#include<queue>
#include<cstring>
using namespace std;
struct PP{
	int kx;
	int ky;
	int tx;
	int ty;
	int Z;
};
int w,h;
PP S;
bool A[52][52][52][52],D[52][52];
int main(){
	queue<PP> P;
	int d=0,i=0,j=0,l=-1;
	int tx[4]={ 1, 0,-1,0 };       
	int kx[4]={-1, 0, 1,0 };
	int ty[4]={ 0, 1, 0,-1 };
	int ky[4]={ 0, -1, 0,1};
	cin>>w>>h;
	while(w!=0||h!=0){
		memset(A,0,sizeof(A));
		for(i=0;i<=h+1;i++){
			for(j=0;j<=w+1;j++){
				D[i][j]=1;
			}
		}

		cin>>S.tx>>S.ty;
		cin>>S.kx>>S.ky;
		for(i=1;i<=h;i++){
			for(j=1;j<=w;j++){
				cin>>D[i][j];
			}
		}
		S.Z=0;
		P.push(S);
		if(S.tx==S.kx&&S.ty==S.ky){
			d=-1;
			cout<<S.Z<<endl;
		}
		while(d!=-1){
			l++;
			if(l==4){
				l=0;
				S=P.front();
				P.pop();
				if(P.empty()){
					cout<<"NA"<<endl;
					break;
				}
			}
			S=P.front();

			S.tx=S.tx+tx[l];
			S.ty=S.ty+ty[l];
			S.kx=S.kx+kx[l];
			S.ky=S.ky+ky[l];
			if(A[S.ty][S.tx][S.ky][S.kx]==1||(D[S.ty][S.tx]==1&&D[S.ky][S.kx]==1)){
				continue;
			}
			A[S.ty][S.tx][S.ky][S.kx]=1;

			if(D[S.ty][S.tx]==1){
				S.tx=S.tx-tx[l];
				S.ty=S.ty-ty[l];
			}
			if(D[S.ky][S.kx]==1){
				S.kx=S.kx-kx[l];
				S.ky=S.ky-ky[l];
			}
			//saka();
			S.Z++;
			P.push(S);
			if(S.tx==S.kx&&S.ty==S.ky){
				cout<<S.Z<<endl;
				break;
			}	
			if(S.Z==100){
				cout<<"NA"<<endl;
				break;
			}


		}
		while(!P.empty()){
			P.pop();
		}
		d=0;
		l=-1;
		cin>>w>>h;
	}	
	return 0;
}