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>
#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).at(y+j) = 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<bits/stdc++.h>
using namespace std;
int w,h,sy,sx,gx,gy,n;
int color;
int c,d,x,y;
int dx[4]={1,0,-1,0};
int dy[4]={0,-1,0,1};
int maps[105][105];
int mem[105][105];
int dfs(int nowx,int nowy);
main(){
  while(1){
    cin>>w>>h;
    if(w==0&&h==0)break;
    cin>>sx>>sy>>gx>>gy;
    cin>>n;
    memset(maps,0,sizeof(maps));
    memset(mem,0,sizeof(maps));
    for(int i=0;i<n;i++){
      cin>>c>>d>>x>>y;
      for(int i=0;i<4;i++){
	if(d==0){
	  maps[y][x+i]=c;
	  maps[y+1][x+i]=c;
	}
	else{
	  maps[y+i][x]=c;
	  maps[y+i][x+1]=c;
	}
      }
    }
    /*
    for(int i=1;i<=h;i++){
      for(int j=1;j<=w;j++){
	cout<<maps[i][j]<<" ";
      }
      cout<<endl;
    }
    */
    color=maps[sy][sx];
    if(dfs(sx,sy)==1){
      cout<<"OK"<<endl;
    }
    else{
      cout<<"NG"<<endl;
    }
  }
}
int dfs(int nowx,int nowy){
  int check=0;
  if(nowx==gx&&nowy==gy){
    return 1;
  }
  else{
    for(int i=0;i<4;i++){
      if(nowx+dx[i]>=1&&nowx+dx[i]<=w&&nowy+dy[i]>=1&&nowy+dy[i]<=h&&maps[nowy+dy[i]][nowx+dx[i]]==color&&mem[nowy+dy[i]][nowx+dx[i]]==0){
	mem[nowy+dy[i]][nowx+dx[i]]=1;
	check=max(dfs(nowx+dx[i],nowy+dy[i]),check);
      }
    }
    return check;
  }
}

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

int dx[4] = { 1, 0, -1, 0 };
int dy[4] = { 0, 1, 0, -1 };


class cordinate
{

public:
	int x;
	int y;

};

int main()
{
	while(1)
	{


		int w;
		int h;
		cin >> w >> h; 
		if(w == 0 && h == 0)
		{
			break;
		}
		w = 110;
		h = 110;
		
		int xs;
		int ys;
		cin >> xs >> ys;
		int xg;
		int yg;
		cin >> xg >> yg;
		int n;
		cin >> n;

		vector<vector<int >> vobj;

		for(int i = 0; i < h; i++)
		{
			vector<int> lineobj;
			for(int j = 0; j < w; j++)
			{

				lineobj.push_back(0);

			}
			vobj.push_back(lineobj);

		}
		for(int i = 0; i < n; i++)
		{
			int c, d, x, y;
			cin >> c >> d >> x >> y;
			x--;
			y--;

			if(d == 0)
			{
				vobj[x][y] = c;
				vobj[x + 1][y] = c;
				vobj[x + 2][y] = c;
				vobj[x + 3][y] = c;
				vobj[x][y + 1] = c;
				vobj[x + 1][y + 1] = c;
				vobj[x + 2][y + 1] = c;
				vobj[x + 3][y + 1] = c;
			}
			else if(d == 1)
			{
				vobj[x][y] = c;
				vobj[x][y + 1] = c;
				vobj[x][y + 2] = c;
				vobj[x][y + 3] = c;
				vobj[x + 1][y] = c;
				vobj[x + 1][y + 1] = c;
				vobj[x + 1][y + 2] = c;
				vobj[x + 1][y + 3] = c;
			}
		}

		int startColor;
		startColor = vobj[xs - 1][ys - 1];
		queue<cordinate> que;

		cordinate obj;
		obj.x = xs - 1;
		obj.y = ys - 1;
		que.push(obj);
		bool flag = false;
		while(1)
		{
			if(startColor == 0)
			{
				break;
			}
			cordinate buf;
			buf = que.front();
			que.pop();

			int bx;
			int by;
			bx = buf.x;
			by = buf.y;
			if(bx == xg - 1 && by == yg - 1)
			{
				flag = true;
				break;
			}
			for(int i = 0; i < 4; i++)
			{
				if(bx + dx[i] >= 0 && bx + dx[i] <= h - 1)
				{
					if(by + dy[i] >= 0 && by + dy[i] <= w - 1)
					{
						if(vobj[bx + dx[i]][by + dy[i]] == startColor)
						{
							cordinate newObject;
							newObject.x = bx + dx[i];
							newObject.y = by + dy[i];
							que.push(newObject);

						}
					}
				}
			}
			vobj[bx][by] = -1;

			if(que.size() == 0)
			{
				break;
			}
		}


		if(flag == true)
		{
			cout << "OK" << endl;
		}
		else{
			cout << "NG" << endl;
		}
		/*for(int i = 0; i < w - 1; i++)
		{
			for(int j = 0; j < h - 1; j++)
			{
				cout << vobj[i][j] << " ";
			}
			cout << endl;
		}  */

	}



}