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>
using namespace std;

char F[102][102];

void Block(int c,int d,int x,int y){
	if(d==0){
    	for(int i=0;i<4;i++){
    		F[y  ][x+i]=c;
			F[y+1][x+i]=c;
    	}
  	}else{
    	for(int i=0;i<4;i++){
    		F[y+i][x  ]=c;
    		F[y+i][x+1]=c;
    	}
	}
}
void DFS(int y,int x,int c){
	if(F[y][x]!=c)
		return;

	F[y][x] = 6;

    DFS(y-1,x  ,c);
    DFS(y  ,x+1,c);
    DFS(y+1,x  ,c);
    DFS(y  ,x-1,c);
}
int main(){
	while(true){
		int w,h,xs,ys,xg,yg,n;
		cin >> w >> h;
		if(w==0&&h==0){break;}
		for(int i=0;i<h;i++){
			for(int k=0;k<w;k++){
				F[i][k]=-1;
			}
		}
		cin >> xs >> ys;
		cin >> xg >> yg;
		cin >> n;
		for(int i=0; i<n; i++){
			int c,d,x,y;
			cin >> c >> d >> x >> y;
			Block(c,d,x,y);
  		}
 		DFS(ys,xs,F[ys][xs]);
		if(F[yg][xg]==6){
			cout << "OK" << endl;
		}else{
			cout << "NG" << endl;
		}
	}
  return 0;
}

C++: #include<iostream>
#include<stack>
#include<string.h>
using namespace std;
struct ST {
	int a;
	int b;
	int c;
};
long long brock[1000][1000];
long long ds[1000][1000];
int q[4]={0,-1,0,1};
int p[4]={1,0,-1,0};
int main(){
	stack <ST> S;
	ST ma;
	ST ba;
	int w,h;//???????????§??????
	int xs,ys;//??????????????§?¨?
	int xg,yg;//??´????????§?¨?
	int n;//????????????????????°
	int c,d,x,y;//????????????????????±
	int i,j,m,check=0;
	while(1){
		memset(ds,0,sizeof(ds));
		memset(brock,0,sizeof(brock));
		cin>>w>>h;//???????????§????????\???
		if(w==0&&h==0){
			break;
		}
		cin>>xs>>ys>>xg>>yg;//??????????????¨??´???????????§?¨???\???
		cin>>n;//????????????????????°
		for(i=0;i<n;i++){
			cin>>c>>d>>x>>y;
			if(d==0){
				for(m=y;m<y+2;m++){
					for(j=x;j<x+4;j++){
						brock[m][j]=c;
					}
				}
			}
			else{
				for(m=y;m<y+4;m++){
					for(j=x;j<x+2;j++){
						brock[m][j]=c;
					}
				}
			}
		}
		for(i=1;i<h;i++){
			for(j=1;j<w;j++){
				cout<<brock[i][j];
			}
			cout<<endl;
		}
		if(brock[ys][xs]!=brock[yg][xg]){
			cout<<"NG"<<endl;
		}
		else{
			ma.a=ys;
			ma.b=xs;
			ma.c=brock[ys][xs];
			ds[ys][xs]=1;
			S.push(ma);
			check=0;
			while(!S.empty()){
				ba=S.top();
				S.pop();
				ds[ba.a][ba.b]=1;
				if(ba.a==yg&&ba.b==xg){
					check=1;
					break;
				}
				if(ba.c==brock[yg][xg]){
					for(i=0;i<4;i++){
						if(ba.a+p[i]>0&&ba.a+p[i]<=h&&ba.b+q[i]>0&&ba.b+q[i]<=w&&ds[ba.a+p[i]][ba.b+q[i]]==0){
							ma.a=ba.a+p[i];
							ma.b=ba.b+q[i];
							ma.c=brock[ba.a+p[i]][ba.b+q[i]];
							S.push(ma);
						}
					}
				}
			}
			if(check==1){
				cout<<"OK"<<endl;
			}
			else{
				cout<<"NG"<<endl;
			}
		}
	}
	return 0;
}

C++: #include<iostream>
#include<string>
#include<string.h>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<stdlib.h>
#include<queue>
#include<map>
#include<vector>
#include<list>
#include<stack>
#include<functional>

using namespace std;

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

typedef unsigned long long ull; typedef long long ll;

const int INF=100000000; int dx[4]={1,0,-1,0}; int dy[4]={0,1,0-1};

typedef pair<int ,int > P;

char maze[105][105];

int sx,sy; int gx,gy; int w,h;

char sc; //スタート地点のカラー

//stdin //stdout

void dfs(int x,int y) { maze[x][y]='9';

for(int i=-1;i<=1;i++) { for(int j=-1;j<=1;j++) { int nx=x+i; int ny=y+j;

if(0<=nx && nx<=w && 0<=ny && ny<=h &&maze[nx][ny] != '0'&&maze[nx][ny] != '9') { dfs(nx,ny); }

} } return ; }

void solve() {

rep(i,101) rep(j,101) maze[i][j]='0';

int n; char c; int d; int x,y;

cin>>sy>>sx; cin>>gy>>gx;

cin>>n;

rep(i,n) { cin>>c>>d>>y>>x;

if(d==1) { rep(i,4) { rep(j,2) { maze[x+i][y+j]=c;

} } } else if (d==0) { rep(i,2) { rep(j,4) { maze[x+i][y+j]=c;

} } }

} //6 6 //1 1 //3 6 //2 //1 0 1 1 //1 1 3 3 // rep(i,w+1) // { // rep(j,h+1) // { // cout<<maze[i][j]; //// } // cout<<endl; // } //// cout<<maze[gx][gy]<<endl;

if(maze[sx][sy]=='0') { cout<<"NG"<<endl; return; } else { sc=maze[sx][sy]; dfs(sx,sy); }

//rep(i,w+1) //{ // rep(j,h+1) // { // cout<<maze[i][j];

// } // cout<<endl; //}

if(maze[gx][gy]=='9') { cout<<"OK"<<endl; return; } else { cout<<"NG"<<endl; return; }

}

int main() {

while(cin>>w>>h) { if(w==0 && h==0) { return 0; } else { solve(); } }

return 0; }