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 <bits/stdc++.h>

using namespace std;

#define all(c) (c).begin(), (c).end()
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

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

int w, h;
int xs, ys;
int xg, yg;
int maze[102][102];

using P = pair<int, int>;
void solve() {
    int c = maze[ys][xs];
    queue<P> que;
    que.push(P(ys, xs));
    set<P> visited;
    visited.insert(P(ys, xs));
    bool ok = false;
    while (que.size()) {
        auto p = que.front();
        que.pop();
        int y = p.first;
        int x = p.second;
        if (yg == y && xg == x) ok = true;
        rep(k, 4) {
            int ny = y + dy[k];
            int nx = x + dx[k];
            if (ny < 0 || nx < 0) continue;
            if (h <= ny || w <= nx) continue;
            if (maze[ny][nx] != c) continue;
            if (visited.count(P(ny, nx))) continue;
            visited.insert(P(ny, nx));
            que.push(P(ny, nx));
        }
    }
    cout << (ok ? "OK" : "NG") << endl;
}

int main() {
    while (cin >> w >> h, w) {
        rep(i, 102) rep(j, 102) maze[i][j] = -1;
        cin >> xs >> ys;
        cin >> xg >> yg;
        xs--, ys--;
        xg--, yg--;
        int n;
        cin >> n;
        rep(_, n) {
            int c, d, x, y;
            cin >> c >> d >> x >> y;
            if (d == 0) {
                rep(i, 2) rep(j, 4) maze[y + i][x + j] = c;
            } else {
                rep(i, 4) rep(j, 2) maze[y + i][x + j] = c;
            }
        }
        solve();
    }

    return 0;
}

C++: #include<stdio.h>
#include<string.h>
void haichi(void);
int Block(int,int);
int c,d,x,y,xg,yg,w,h,M,Flag;
int MAP[101][101],MF[101][101];
int main(void)
{
	int xs,ys,n;
	while(1){
		Flag=0;
		memset(MAP,0,sizeof(MAP));
		memset(MF,0,sizeof(MF));
		scanf("%d %d",&w,&h);
		if(w == 0 && h == 0) break;
		scanf("%d %d %d %d",&xs,&ys,&xg,&yg);
		scanf("%d",&n);
		for(int i=0;i<n;i++){
			scanf("%d %d %d %d",&c,&d,&x,&y);
			haichi();
		}
		/*for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				printf("%d",MAP[i][j]);
			}
			printf("\n");
		}*/
		M = MAP[ys][xs];//
		if(Block(xs,ys))
			printf("OK\n");
		else
			printf("NG\n");
	}
	return 0;
}

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

int Block(int X,int Y)
{
	
	//printf("%d",M);
	printf("%d %d\n",X,Y);
	if(X == xg && Y == yg)
		return 1;
	if(MAP[Y][X] != M || MF[Y][X] == 1 || X < 1 || Y < 1 || X > w || Y > h) return 0;
	MF[Y][X] = 1;
	return Block(X,Y-1) || Block(X,Y+1) || Block(X-1,Y) || Block(X+1,Y);
}

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

int F[102][102];

bool DFS(int Y, int X, int C, int yg, int xg)
{
  if(Y == yg && X == xg)
    return true;
  if(F[Y][X]!=C)
    return false;

  F[Y][X] = 0;

  bool tmp = 0;
  tmp += DFS(Y-1, X, C, yg, xg);
  tmp += DFS(Y+1, X, C, yg, xg);
  tmp += DFS(Y, X-1, C, yg, xg);
  tmp += DFS(Y, X+1, C, yg, xg);
  return tmp;
}

int main()
{
  while(1){
    int w, h;
    cin >> w >> h;

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

    int xs, ys;
    cin >> xs >> ys;

    int xg, yg;
    cin >> xg >> yg;

    int n;
    cin >> n;

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

    bool res = DFS(ys, xs, F[ys][xs], yg, xg);

    if(res)
      cout << "OK" << endl;
    else
      cout << "NG" << endl;
  }
}

C++: #include<iostream>
#include<queue>
#include<vector>
#include<list>

typedef struct block
{
	int x;
	int y;
	int h;
	int w;
	int color;
}block;

block blocks[1280];

std::queue<int> que;
std::list<int> adjacive[1280];

void makelist(int n);
bool BFS(int start,int goal);

int main()
{
	int n,w,h,xs,ys,xg,yg,start,goal;
	while(1)
	{
		while(!que.empty()){que.pop();}
		start=-1;
		goal=-1;
		std::cin>>w>>h;
		if(w==0&&h==0)break;
		std::cin>>xs>>ys>>xg>>yg>>n;
		for(int i=0;i<n;i++)
		{
			int c,d,x,y;
			std::cin>>c>>d>>x>>y;
			blocks[i].color=c;
			blocks[i].x=x;
			blocks[i].y=y;
			if(d==0)
			{
				blocks[i].h=2;
				blocks[i].w=4;
			}
			else
			{
				blocks[i].h=4;
				blocks[i].w=2;
			}
			if(blocks[i].x<=xs&&blocks[i].x+blocks[i].w-1>=xs&&blocks[i].y<=ys&&blocks[i].y+blocks[i].h-1>=ys)
			{
				start=i;
			}
			else if(blocks[i].x<=xg&&blocks[i].x+blocks[i].w-1>=xg&&blocks[i].y<=yg&&blocks[i].y+blocks[i].h-1>=yg)
			{
				goal=i;
			}
		}
		makelist(n);
		if(BFS(start,goal))
		{
			std::cout<<"OK"<<std::endl;
		}
		else
		{
			std::cout<<"NG"<<std::endl;
		}
	}
	return 0;
}

void makelist(int n)
{
#define x1 blocks[i].x
#define y1 blocks[i].y
#define h1 blocks[i].h
#define w1 blocks[i].w
#define x2 blocks[j].x
#define y2 blocks[j].y
#define h2 blocks[j].h
#define w2 blocks[j].w

	for(int i=0;i<n;i++)
	{
		adjacive[i].clear();
		for(int j=0;j<n;j++)
		{
			if(blocks[i].color==blocks[j].color)
			{
				if((x1==x2+w2&&y1<=y2+h2-1&&y1+h1-1>=y2)||(x2==x1+w1&&y1<=y2+h2-1&&y1+h1-1>=y2)||(y1==y2+h2&&x1<=x2+w2-1&&x1+w1-1>=x2)||(y2==y1+h1&&x1<=x2+w2-1&&x1+w1-1>=x2))
				{
					adjacive[i].push_back(j);
				}
			}
		}
	}
}

bool BFS(int start,int goal)
{
	int survey;
	que.push(start);
	
	while(!que.empty())
	{
		survey=que.front();
		que.pop();
		for(std::list<int>::iterator it=adjacive[survey].begin();it!=adjacive[survey].end();it++)
		{
				que.push(*it);
		}
		adjacive[survey].clear();
		if(survey==goal)
		{
			return true;
		}
	}
	return false;
}