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 <stdio.h>
#include <queue>
#include <iostream>



#define MAX 150

int map[MAX][MAX];

void makemap(int c, int d, int x, int y);

int bfs(int xs,int ys,int xg,int yg);

int main()
{
	int w,h,xs,ys,xg,yg,n,c,d,x,y;
	//int flag=1;
	while(1)
	{
		scanf("%d%d",&w,&h);
		if(w==0 && h==0)
			return 0;
		scanf("%d%d",&xs,&ys);
		scanf("%d%d",&xg,&yg);
		scanf("%d",&n);

		/*w=20;
		h=20;
		if (flag==0)
		{
			xs=1;
			ys=1;
			xg=9;
			yg=9;
			n=7;
		}
		else
		{
			xs=9;
			ys=9;
			xg=1;
			yg=1;
			n=6;
		}サンプルデータ入力*/
		for(int i=0;i<MAX;i++)
			for(int j=0;j<MAX;j++)
				map[i][j]=0;
		/*if (flag==0)
		{
			makemap(2,0,1,1);
			makemap(5,1,1,3);
			makemap(2,1,3,3);
			makemap(1,1,5,2);
			makemap(5,1,7,3);
			makemap(2,0,2,7);
			makemap(2,0,6,8);
		}
		else
		{
			makemap(2,0,1,1);
			makemap(1,0,5,1);
			makemap(2,1,1,3);
			makemap(5,0,1,7);
			makemap(3,1,5,5);
			makemap(4,1,8,5);
		}サンプルデータ入力２*/

		for(int i=0;i<n;i++)
		{
			printf("b%d\n",i+1);
			scanf("%d%d%d%d",&c,&d,&x,&y);
			makemap(c,d,x,y);
		}
		

		/*for(int i=0;i<MAX;i++)
		{
			for(int j=0;j<MAX;j++)
				printf("%d",map[i][j]);
			printf("\n");
		}マップの表示*/

		if(bfs(xs,ys,xg,yg)==0)
			printf("OK\n");
		else
			printf("NG\n");
}
	return 0;
}

void makemap(int c, int d, int x, int y)
{
	if(d==0)
		for(int i=x+1;i<x+5;i++)
			for(int j=y+1;j<y+3;j++)
				map[i][j]=c;
	else
		for(int i=x+1;i<x+3;i++)
			for(int j=y+1;j<y+5;j++)
				map[i][j]=c;
}

int bfs(int xs,int ys,int xg,int yg)
{
	int startcolor=map[xs][ys];
	int nowx=xs,nowy=ys;
	using namespace std;
	queue<int> x;
	queue<int> y;
	while(1)
	{
		if(nowx==xg && nowy == yg && map[nowx][nowy]==startcolor )
			return 0;
		map[nowx][nowy]=0;
		if(map[nowx-1][nowy]==startcolor)
		{
			x.push(nowx-1);
			y.push(nowy);
		}
		if(map[nowx][nowy-1]==startcolor)
		{
			x.push(nowx);
			y.push(nowy-1);
		}
		if(map[nowx][nowy+1]==startcolor)
		{
			x.push(nowx);
			y.push(nowy+1);
		}
		if(map[nowx+1][nowy]==startcolor)
		{
			x.push(nowx+1);
			y.push(nowy);
		}
		if(x.empty()==1 && y.empty()==1)
			return 1;
		nowx=x.front();
		nowy=y.front();
		x.pop();
		y.pop();
	}
	/*bool visit[MAX][MAX];
	for(int i=0;i<MAX;i++)
		for(int j=0;j<MAX;j++)
			visit[i][j]=0;
	while(1)
	{
		//visit[nowx][nowy]=1;
		if(nowx==xg && nowy == yg && map[nowx][nowy]==startcolor )
			return 0;
		map[nowx][nowy]=0;
		if(map[nowx-1][nowy]==startcolor && visit[nowx-1][nowy]==0)
		{
			x.push(nowx-1);
			y.push(nowy);
		}
		if(map[nowx][nowy-1]==startcolor && visit[nowx][nowy-1]==0)
		{
			x.push(nowx);
			y.push(nowy-1);
		}
		if(map[nowx][nowy+1]==startcolor && visit[nowx][nowy+1]==0)
		{
			x.push(nowx);
			y.push(nowy+1);
		}
		if(map[nowx+1][nowy]==startcolor && visit[nowx+1][nowy]==0)
		{
			x.push(nowx+1);
			y.push(nowy);
		}
		if(x.empty()==1 && y.empty()==1)
			return 1;
		nowx=x.front();
		nowy=y.front();
		x.pop();
		y.pop();
	}*/
}

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



typedef vector<vector<int> > Matrix;
int w,h,xs,ys,xg,yg,n,flag;

class Block{
public:
  int color;
  int direction;
  int x,y,dx,dy;
  void write(Matrix &board){
    if(direction == 0)
      dx = 4,dy = 2;
    else if(direction == 1)
      dx = 2,dy = 4;
    for(int i=0; i<dx; ++i){
      for(int j=0; j<dy; ++j){
	(board.at(x+i-1)).at(y+j-1) = color;
      }
    }
  }
};
  
void func(Matrix &board,int nx,int ny){
  if( nx==xg && ny==yg) flag = 1;
  else if( w<=nx+1 || h<=ny+1) return;
  if(board[nx][ny]==board[nx+1][ny])
    func(board,nx+1,ny);
  if(board[nx][ny]==board[nx][ny+1])
    func(board,nx,ny+1);
}


int main(void){
  string res;
  while(1){
    cin >> w >> h;
    if( w==0 && h==0) return 0;
    cin >> xs >> ys >> xg >> yg >> n;
    Block *object;
    object = new Block[n];
    Matrix board(w, vector<int>(h,0));
    for(int i=0; i<n; ++i){
      cin >> object[i].color;
      cin >> object[i].direction;
      cin >> object[i].x;
      cin >> object[i].y;
      object[i].write(board);
    }
    func(board,xs,ys);
    if(flag==1) res = "OK";
    else res = "NG";
    cout << res << endl;
    flag = 0;
    delete[] object;
    board.clear();
  }
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include<map>
#include<set>
#include<utility>
#include<vector>
#include<cmath>
#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 it ::iterator
#define all(in) in.begin(),in.end()
const double PI=acos(-1);
const double ESP=1e-10;
using namespace std;
int sx,sy,gx,gy,col;
bool func(vector<vector<int> >out,vector<vector<bool> >&out2,int x,int y){
  out2[x][y]=true;
  loop(i,-1,2)loop(j,-1,2){
    if(out2[x+i][y+j]!=true&&out[x+i][y+j]==col)func(out,out2,x+i,y+j);
  }
}
int main(){
  int n,m;
  while(cin>>m>>n,n|m){
    cin>>sx>>sy>>gx>>gy;
    int nn;cin>>nn;
    vector<vector<int> >out(n+2);
    vector<vector<bool> >out2(n+2);
    rep(i,n+2)rep(j,m+2)out[i].pb(0);
    rep(i,n+2)rep(j,m+2)out2[i].pb(false);
    rep(q,nn){
      int a,b,c,d;
      cin>>a>>b>>d>>c;
      if(b)rep(i,4)rep(j,2)out[i+c][j+d]=a;
      else rep(i,2)rep(j,4)out[i+c][j+d]=a;
    }
    /*cout<<endl;
    rep(i,n){
      rep(j,m)cout<<" "<<out[i+1][j+1];
      cout<<endl;
      }*/
    
    if(out[gx][gy]==0||out[gx][gy]!=out[sx][sy]||out[sx][sy]==0){
      cout<<"NG"<<endl;
      continue;
    }
    col=out[sx][sy];
    func(out,out2,sx,sy);
    if(out2[gx][gy])cout<<"OK"<<endl;
    else cout<<"NG"<<endl;
    /*rep(i,n){
      rep(j,m)cout<<" "<<out[i+1][j+1];
      cout<<endl;
      }*/
  }
}