Go: package main

import (
	"bufio"
	"os"
	"strings"
	"strconv"
	"fmt"
)

var scanner = bufio.NewScanner(os.Stdin)

var (
	dx = []int{0, -1, 0, 1}
	dy = []int{1, 0, -1, 0}
)

func main() {
	for scanner.Scan() {
		buf := strings.Split(scanner.Text(), " ")
		w, _ := strconv.Atoi(buf[0])
		h, _ := strconv.Atoi(buf[1])
		if w == 0 && h == 0 {
			break
		}
		scanner.Scan()
		buf_ := strings.Split(scanner.Text(), " ")
		xs, _ := strconv.Atoi(buf_[0])
		ys, _ := strconv.Atoi(buf_[1])
		scanner.Scan()
		buf__ := strings.Split(scanner.Text(), " ")
		xg, _ := strconv.Atoi(buf__[0])
		yg, _ := strconv.Atoi(buf__[1])
		xs--
		ys--
		xg--
		yg--
		scanner.Scan()
		n, _ := strconv.Atoi(scanner.Text())
		field := make([][]int, 100)
		for i := range  field {
			field[i] = make([]int, 100)
		}
		visited := make([][]bool, 100)
		for i := range visited {
			visited[i] = make([]bool, 100)
		}
		for i := 0; i < n; i++ {
			scanner.Scan()
			buf___ := strings.Split(scanner.Text(), " ")
			c, _ := strconv.Atoi(buf___[0])
			d, _ := strconv.Atoi(buf___[1])
			x, _ := strconv.Atoi(buf___[2])
			y, _ := strconv.Atoi(buf___[3])
			x--
			y--
			switch d {
			case 0:
				for j := 0; j < 4; j++ {
					for k := 0; k < 2; k++ {
						field[x+j][y+k] = c
					}
				}
			case 1:
				for j := 0; j < 2; j++ {
					for k := 0; k < 4; k++ {
						field[x+j][y+k] = c
					}
				}
			}
		}
		if field[xs][ys] != field[xg][yg] || // スタートとゴールの色が等しくないと"NG"
			field[xs][ys] == 0 { // スタートの色が無職
			fmt.Println("NG")
			continue
		}
		Q := make([]Entry, 0)
		visited[xs][ys] = true
		Q = append(Q, Entry{xs, ys})
		for len(Q) > 0 {
			row := Q[0].x
			col := Q[0].y
			Q = Q[1:]
			for i := 0; i < 4; i++ {
				if 0 <= row+dx[i] && row+dx[i] < w &&
					0 <= col+dy[i] && col+dy[i] < h && // 移動可能な範囲内かどうか
					!visited[row + dx[i]][col + dy[i]] && // 訪問済みか
					field[row+dx[i]][col+dy[i]]==field[row][col] { // 色が同じかどうか
						visited[row+dx[i]][col+dy[i]] = true
						Q = append(Q, Entry{row+dx[i],col+dy[i]})
				}
			}
		}
		if visited[xg][yg] {
			fmt.Println("OK")
		} else {
			fmt.Println("NG")
		}
	}
}

type Entry struct {
	x, y int
}

C++: #include <iostream>
using namespace std;

int F[102][102] = { 0 };

void DFS(int Y, int X, int c) {
	//cout << Y << " " << X << endl;
	if (F[Y][X] != c)
		return;
	F[Y][X] = 10;
	DFS(Y - 1, X, c);//???
					 //DFS(Y - 1, X+1, A_ito);//??????
	DFS(Y, X + 1, c);//???
					 //DFS(Y + 1, X+1, A_ito);//??????
	DFS(Y + 1, X, c);//???
					 //DFS(Y + 1, X-1, A_ito);//??????
	DFS(Y, X - 1, c);//???
					 //DFS(Y - 1, X-1, A_ito);//??????
}


int main()
{
	int xs, ys, xg, yg, n;
	int c, d, x, y;
	int W = 1, H = 1;

	while (true) {
		cin >> W >> H;
		if ((W == 0) && (H == 0)) {
			break;
		}
		cin >> xs >> ys >> xg >> yg >> n;
		for (int i = 1;i <= n;i++) {
			cin >> c >> d >> x >> y;
			if (d == 0) {
				F[x][y] = c;
				F[x][y + 1] = c;
				F[x + 1][y] = c;
				F[x + 1][y + 1] = c;
				F[x + 2][y] = c;
				F[x + 2][y + 1] = c;
				F[x + 3][y] = c;
				F[x + 3][y + 1] = c;
			}
			if (d == 1) {
				F[x][y] = c;
				F[x + 1][y] = c;
				F[x][y + 1] = c;
				F[x + 1][y + 1] = c;
				F[x][y + 2] = c;
				F[x + 1][y + 2] = c;
				F[x][y + 3] = c;
				F[x + 1][y + 3] = c;
			}
		}
		if (F[ys][xs] != 0)
			DFS(ys, xs, F[ys][xs]);

		if (F[yg][xg] == F[ys][yg]) {
			cout << "OK" << endl;
		}
		else { cout << "NG" << endl; }
		for (int i = 0;i <= H;i++) {
			for (int j = 0;j <= W;j++) {
				F[i][j] = 0;
			}
		}

	}

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

#define int long long
typedef vector<int>vint;
typedef pair<int,int>pint;
typedef vector<pint>vpint;
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define all(v) (v).begin(),(v).end()
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
#define pb push_back
#define mp make_pair
#define fi first
#define se second
template<typename A,typename B>inline void chmin(A &a,B b){if(a>b)a=b;}
template<typename A,typename B>inline void chmax(A &a,B b){if(a<b)a=b;}

int dx[]={-1,0,1,0};
int dy[]={0,-1,0,1};

int H,W,sy,sx,gy,gx;
int N;

int C[100][100];
bool vis[100][100];

void dfs(int y,int x){
    vis[y][x]=true;
    rep(i,4){
        int ny=y+dy[i],nx=x+dx[i];
        if(ny<0||ny>=H||nx<0||nx>=W||C[ny][nx]!=C[y][x]||vis[ny][nx])continue;
        dfs(ny,nx);
    }
}

signed main(){
    while(cin>>W>>H,W||H){
        cin>>sx>>sy>>gx>>gy;
        cin>>N;
        sy--;sx--;gy--;gx--;
        memset(C,0,sizeof(C));
        rep(i,N){
            int c,d,x,y;
            cin>>c>>d>>x>>y;
            x--;y--;
            for(int dy=0;dy<2;dy++){
                for(int dx=0;dx<4;dx++){
                    int ny,nx;
                    if(!d)ny=y+dy,nx=x+dx;
                    else ny=y+dx,nx=x+dy;
                    C[ny][nx]=c;
                }
            }
        }
        if(!C[sy][sx]){
            cout<<"NG"<<endl;
            continue;
        }
        memset(vis,0,sizeof(vis));
        dfs(sy,sx);
        if(vis[gy][gx])cout<<"OK"<<endl;
        else cout<<"NG"<<endl;
    }
    return 0;
}

C++: #include <iostream>
using namespace std;

int weight, hight;
int g[101][101];
int sc;
int sx, sy, gx, gy;
bool flag = false;
const int vx[4] = {0, 0, -1, 1};
const int vy[4] = {1, -1, 0, 0};

void dfs(int x, int y){
    if(x == gx && y == gy){
        flag = true;
        return;
    }

    for(int i = 0;i < 4;i++){
        int nx = x + vx[i];
        int ny = y + vy[i];
        
        if(nx >= 0 && nx < weight && ny >= 0 && ny < hight && g[ny][nx] == sc){
            g[y][x] = 8;
            dfs(nx, ny);
        }
    }
}

int main(){ 
    while(1){
        cin >> weight >> hight;

        if(weight == 0 && hight == 0){
            break;
        }
        
        int dn, c, d, x, y;
        flag = false;
        g[101][101] = {};
        
        cin >> sx >> sy >> gx >> gy >> dn;
        
        for(int i = 0;i < dn;i++){
            cin >> c >> d >> x >> y;
            
            if(d == 0){
                for(int h = 0;h < 2;h++){
                    for(int w = 0;w < 4;w++){
                        g[y+h][x+w] = c;
                    }
                }
            }else{
                for(int h = 0;h < 4;h++){
                    for(int w = 0;w < 2;w++){
                        g[y+h][x+w] = c;
                    }
                }
            }
        }
        
        sc = g[sy][sx];
        dfs(sx, sy);
        
        if(flag){
            cout << "OK" << endl;
        }else{
            cout << "NG" << endl;
        }
    }
    
    return 0;
}

C++: #include<iostream>
using namespace std;

int F[102][102];

void
DFS (int Y, int X, int A)
{
  if (F[Y][X] != A)
    return;

  F[Y][X] = 7;

  DFS (Y - 1, X, A);
  DFS (Y, X + 1, A);
  DFS (Y + 1, X, A);
  DFS (Y, X - 1, A);
}

int
main ()
{
  int w, h;
  int xs, ys;
  int xg, yg;
  int n;
  int c, d, x, y;

  while (true)
    {
      cin >> w >> h;
      if (w == 0 && h == 0)
	break;
      cin >> xs >> ys;
      cin >> xg >> yg;
      cin >> n;




      for (int b = 1; b <= h; b++)
	{
	  for (int a = 1; a <= w; a++)
	    {
	      F[b][a] = 0;
	    }
	}

      for (int i = 0; i < n; i++)
	{
	  cin >> c >> d >> x >> y;
	  if (d == 0)
	    {
	      for (int a = 0; a < 4; a++)
		{
		  for (int b = 0; b < 2; b++)
		    {
		      F[y + b][x + a] = c;
		    }
		}

	    }
	  else
	    {
	      for (int a = 0; a < 2; a++)
		{
		  for (int b = 0; b < 4; b++)
		    {
		      F[y + b][x + a] = c;
		    }
		}
	    }

	}


      if (F[ys][xs] == 1 || F[ys][xs] == 2 || F[ys][xs] == 3
	  || F[ys][xs] == 4 || F[ys][xs] == 5)
	{
	  DFS (ys, xs, F[ys][xs]);
	}

      if (F[yg][xg] == F[ys][xs])
	{
	  cout << "OK" << endl;
	}
      else
	{
	  cout << "NG" << endl;
	}

      for (int y = 1; y <= h; y++)
	{
	  for (int x = 1; x <= w; x++)
	    {
	      cout << F[y][x];
	    }
         cout << endl;
	}

    }

  return 0;
}