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 <string>
using namespace std;

string ans;
int w,h,gx,gy;
int map[110][110];
int dx_[4] = {0,1,0,-1};
int dy_[4] = {1,0,-1,0};
int dx[2][8] = {
	{0,1,2,3,0,1,2,3},
	{0,1,0,1,0,1,0,1}
};
int dy[2][8] = {
	{0,0,0,0,1,1,1,1},
	{0,0,1,1,2,2,3,3},
};
void solve(int x,int y,int color){
	if( ans == "OK" || color == 0 /*|| map[y][x] != color*/ ) return;
	//if( x<0 || x>w || y<0 || y>h ) return;

	for(int i=0 ; i<4 ; ++i ){
		int mx = x + dx_[i];
		int my = y + dy_[i];
		if( mx<0 || mx>w || my<0 || my>h ) continue;
		//cout << "x:" << x << " y:" << y << endl;
		
		if( map[my][mx] == color ){
			if( mx == gx && my == gy ){
				ans = "OK";
			}else{
				map[my][mx] = 0;
				solve( mx , my , color );
			}
		}
	}
}

void debug(){
	char c[6] = {' ','#','$','*','+','@'};
	cout << "w:" << w << " h:" << h << " map : " << endl;
	for(int y=0 ; y<h ; ++y ){
		for(int x=0 ; x<w ; ++x ){
			cout << c[ map[y][x] ];
		}
		cout << endl;
	}
}

int main(){
	int sx,sy,n;
	
	while( cin >> w >> h , w|h ){
		ans = "NG";
		for(int y=0 ; y<110 ; ++y )
			for(int x=0 ; x<110 ; ++x )
				map[y][x] = 0;

		cin >> sx >> sy >> gx >> gy >> n ;
		for(int i=0 ; i<n ; ++i ){
			int c,d,x,y;
			cin >> c >> d >> x >> y;
			for(int j=0 ; j<8 ; j++){
				int mx = x + dx[d][j];
				int my = y + dy[d][j];
				map[my][mx] = c;
			}
		}
		//debug();
		//map[sy][sx] = 0;
		solve( sx , sy , map[sy][sx] );
		//cout << "sx:" << sx << " sy:" << sy << endl;
		cout << ans << endl;
	}
}

C++: #include<stdio.h>
//#include<windows.h>
int main(void)
{
	int w,h;
	int map[101][101];
	int st[2],go[2];
	int i,j,k,l,m;
	int num;
	int b_c,b_ang,b_x,b_y;
	int sign;
	int ans;
	int maps=0;
	int flag;
	
	for(;;)
	{
		ans=0;
		
		for(i=0;i<100;i++)
		{
			for(j=0;j<100;j++)
				map[i][j]=0;
		}
		
		scanf("%d%d",&w,&h);
		
		if(w==0 && h==0)
			break;
		
		scanf("%d%d%d%d",&st[0],&st[1],&go[0],&go[1]);
		
		
		scanf("%d",&num);
		
		for(i=0;i<num;i++)
		{
			scanf("%d%d%d%d",&b_c,&b_ang,&b_x,&b_y);
			
			if(b_ang==0)
			{
				for(j=0;j<4;j++)
				{
					for(k=0;k<2;k++)
						map[b_x+j][b_y+k]=b_c;
				}
			}
			else
			{
				for(j=0;j<4;j++)
				{
					for(k=0;k<2;k++)
						map[b_x+k][b_y+j]=b_c;
				}
			}
		}
		
		if(map[st[0]][st[1]]==0 || map[go[0]][go[1]]==0)
			printf("NG");
		else
		{
			sign=map[st[0]][st[1]];
			flag=0;
			
			for(i=0;i<w;i++)
			{
				for(j=0;j<h;j++)
				{
					if(map[i][j]!=sign)
						map[i][j]=0;
					else
						maps++;
				}
			}
			
			map[st[0]][st[1]]=-1;
			map[go[0]][go[1]]=-2;
			
			for(i=st[0],j=st[1];;)
			{
				
/*
				for(m=0;m<h;m++)
				{
					for(l=0;l<w;l++)
					{
						printf("%d ",map[l][m]);
					}
					printf("%dツ行\n",l);
				}
				getchar();
				system("cls");
*/
				
				if(map[i+1][j]==-2 || map[i][j+1]==-2 || map[i-1][j]==-2 || map[i][j-1]==-2)
				{
					ans=1;
					break;
				}
				else if(map[i-1][j]!=0 && map[i][j-1]!=0 && map[i+1][j]!=0 && map[i][j+1]!=0)
				{
					if(map[i+1][j]==sign)
					{
						map[i][j]=7;
						i++;
						maps--;
					}
					else if(map[i][j+1]==sign)
					{
						map[i][j]=7;
						j++;
						maps--;
					}
					else if(map[i-1][j]==sign)
					{
						map[i][j]=7;
						i--;
						maps--;
					}
					else if(map[i][j-1]==sign)
					{
						map[i][j]=7;
						j--;
						maps--;
					}
				}
				else if(map[i+1][j]==sign/* && map[i][j-1]!=sign*/)//ツ右
				{
//					printf("migi\n");
					map[i][j]=7;
					i++;
					maps--;
				}
				else if(/*map[i+1][j]!=sign && */map[i][j+1]==sign)//ツ可コ
				{
//					printf("sita1\n");
					map[i][j]=7;
					j++;
					maps--;
				}
				else if(map[i-1][j]==sign/* && map[i][j+1]!=sign*/)//ツ債カ
				{
//					printf("hidari\n");
					map[i][j]=7;
					i--;
					maps--;
				}
				else if(/*map[i+1][j]!=sign && */map[i][j-1]==sign)//ツ湘」
				{
//					printf("ue1\n");
					map[i][j]=7;
					j--;
					maps--;
				}
				else if(/*map[i-1][j]!=sign && */map[i][j+1]==sign)//ツ可コ
				{
//					printf("sita2\n");
					map[i][j]=7;
					j++;
					maps--;
				}
				else if(map[i-1][j]!=sign && map[i][j-1]==sign)//ツ湘」
				{
//					printf("ue2\n");
					map[i][j]=7;
					maps--;
					j--;
				}
				else if(map[i+1][j]!=sign && map[i][j+1]!=sign && map[i-1][j]!=sign && map[i][j-1]!=sign && maps==0)
				{
					ans=2;
					break;
				}
				else
				{
					
					map[i][j]=7;
					
					for(m=0;m<h;m++)
					{
						for(l=0;l<w;l++)
						{
							if((map[m][l]==sign && map[m][l+1]==7) || (map[m][l]==sign && map[m-1][l]))
							{
								i=m;
								j=l;
								flag=1;
							}
						}
					}
					if(flag==0)
					{
						ans=2;
						break;
					}
				}
			}
			if(ans==1)
				printf("OK");
			else if(ans==2)
				printf("NG");
		}
	}
}
/*
20 20 
1 1
2 7
7
2 0 1 1
5 1 1 3
2 1 3 3
1 1 5 2
5 1 7 3
2 0 2 7
2 0 6 8
*/