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<stack>
#include<queue>
#include<cstdio>
using namespace std;

#define X_MAX 100+10
#define Y_MAX 100+10

#define Vertical 1
#define Horizontal 0

int my[4] = { 1,-1,0,0 };
int mx[4] = { 0,0,1,-1 };

struct ST
{
	int came[Y_MAX][X_MAX];
	int now_y;
	int now_x;
};


void paint_V(int*map , int col)
{
	int i;
	for (i = 0; i < 2; i++)
	{
		*(map + i) = col;
	}
}

void paint_H(int*map, int col)
{
	int i;
	for (i = 0; i < 4; i++)
	{
		*(map + i) = col;
	}
}


void chek(int map[Y_MAX][X_MAX],int lx,int ly)
{
	int i, j;
	for (i = 0; i <= ly+1;i++)
	{
		for (j = 0; j <= lx+1; j++)
		{
			cout << map[i][j];
		}
		cout << endl;
	}
}


int main(void)
{
	ST an = {0}, tmp;
	queue<ST> ma;

	int lx, ly, n;
	int sx, sy, gx, gy;
	int col, VorH,set_x,set_y;
	int i, j;

	while ((cin >> lx >> ly), lx!=0&&ly!=0)
	{
		int goal = 0;
		int map[Y_MAX][X_MAX] = { 0 };
		cin >> sx >> sy >> gx >> gy >> n;

		for (i = 0; i < n; i++)
		{
			cin >> col >> VorH >> set_x >> set_y;
			if (VorH == Vertical)
			{
				for (j = 0; j < 4; j++)
				{
					paint_V(map[set_y + j] + set_x, col);
				}
			}
			else
			{
				for (j = 0; j < 2; j++)
				{
					paint_H(map[set_y + j] + set_x, col);
				}
			}
		}
		
		int s_col = map[sy][sx];
		if (s_col == 0)
		{
			cout << "NG\n";
			continue;
		}

		an.now_y = sy;
		an.now_x = sx;
		ma.push(an);

		//chek(map, lx, ly);

		while (!ma.empty())
		{
			an = ma.front();
			ma.pop();
			//an.came[an.now_y][an.now_x] = -1;
			if (map[an.now_y][an.now_x] == s_col)
			{
				map[an.now_y][an.now_x] = -1;

				//printf("y=%d,x=%d\n", an.now_y, an.now_x);
				//chek(an.came, lx, ly);

				if (an.now_y == gy && an.now_x == gx)
				{
					goal = 1;
					break;
				}

				tmp = an;

				for (i = 0; i < 4; i++)
				{
					if (map[an.now_y + my[i]][an.now_x + mx[i]] == s_col/* && an.came[an.now_y + my[i]][an.now_x + mx[i]] == 0*/)
					{
						tmp.now_y = an.now_y + my[i];
						tmp.now_x = an.now_x + mx[i];
						ma.push(tmp);
					}
				}
			}
		}
		if (goal == 1)
		{
			while (!ma.empty())
			{
				ma.pop();
			}
			cout << "OK\n";
		}
		else
		{
			cout << "NG\n";
		}


	}
	return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <cassert>
#include <cctype>
#include <complex>
#include <cstdio>
#include <map>
#include <math.h>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>
using namespace std;

int show=1;
int w,h,sx,sy,gx,gy,d[101][101],dx[4]={1,0,-1,0},dy[4]={0,1,0,-1},C;
int field[101][101];
const int INF=9999999;
typedef pair<int,int> P;

void bfs(){
	queue<P> que;
	for(int i=1;i<=h;i++)for(int j=1;j<=w;j++)d[i][j]=INF;
	que.push(P(sy,sx));
	d[sy][sx]=0;
	while(!que.empty()){
		P p=que.front(); que.pop();
		if(p.first==gy&&p.second==gx)break;
		for(int i=0;i<4;i++){
			int ny=p.first+dy[i],nx=p.second+dx[i];
			if(1<=ny&&ny<=h&&1<=nx&&nx<=w&&field[ny][nx]==C&&d[ny][nx]==INF){
			que.push(P(ny,nx));
			d[ny][nx]=d[p.first][p.second]+1;
			}
		}
	}
	if(d[gy][gx]==INF)cout<<"NG"<<endl;
	else cout<<"OK"<<endl;
}

int main() {
	while(cin>>w>>h){
		if(!h)return 0;
		int n,c,di,x,y;
		cin>>sx>>sy>>gx>>gy>>n;
		for(int i=1;i<=h;i++)for(int j=1;j<=w;j++)field[i][j]=0;
		for(int i=0;i<n;i++){
			cin>>c>>di>>x>>y;
			for(int j=y;j<y+2+di*2;j++)for(int k=x;k<x+2+!di*2;k++)field[j][k]=c;
		}
		C=field[1][1];
		if(!C)cout<<"NG"<<endl;
		else bfs();
		if(show){
			for(int i=1;i<=h;i++){for(int j=1;j<=w;j++){if(field[i][j])cout<<field[i][j];else cout<<" ";}cout<<endl;}
			for(int i=1;i<=h;i++){for(int j=1;j<=w;j++){if(d[i][j]<INF)cout<<d[i][j]<<" ";else cout<<"  ";}cout<<endl;}
		}
	}
}

C++: // 2015/07/03 Tazoe

#include <iostream>
using namespace std;

int F[102][102];

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

	F[Y][X] = 6;

	DFS(Y-1, X, C);		// 上
	DFS(Y, X+1, C);		// 右
	DFS(Y+1, X, C);		// 下
	DFS(Y, X-1, C);		// 左
}

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

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

		for(int y=0; y<=h+1; y++){
			for(int x=0; x<=w+1; x++){
				F[y][x] = 0;		// 初期化
			}
		}

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

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

		int n;
		cin >> n;

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

			F[y][x] = F[y][x+1] = F[y+1][x] = F[y+1][x+1] = c;

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

		if(F[ys][xs]==0){
			cout << "NG" << endl;
			continue;
		}

		DFS(ys, xs, F[ys][xs]);

		if(F[yg][xg]==6){
			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 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] == 0 || 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++)
	    {
	      F[y][x] = 0;
	    }
	}

    
   
    }

  return 0;
}