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<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=xs;
			ma.b=ys;
			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<stdio.h>
#include<string.h>
void haichi(void);
void Block(int,int);
int c,d,x,y,xg,yg,M,Flag;
int MAP[101][101],MF[101][101];
int main(void)
{
    int w,h,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(MAP[ys][xs] == MAP[yg][xg])
            Block(xs,ys);
        if(Flag==1)
            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;
    }
}
 
void Block(int X,int Y)
{
    MF[Y][X] = 1;
    //printf("%d",M);
    if(X == xg && Y == yg)
        Flag = 1;
    if(MAP[Y-1][X] == M && MF[Y-1][X] == 0) Block(X,Y-1); //???
    if(MAP[Y+1][X] == M && MF[Y+1][X] == 0) Block(X,Y+1); //???
    if(MAP[Y][X-1] == M && MF[Y][X-1] == 0) Block(X-1,Y); //???
    if(MAP[Y][X+1] == M && MF[Y][X+1] == 0) Block(X+1,Y); //???
}

C++: #include<iostream>
#include<algorithm>
#include<cstring>
using namespace std;
bool N[102][102];
int map[102][102],R,ga,gb,w,h;
bool block(int ,int);
int main()
{
	int i,a,n,b,c,d,X=0,Y=0,x,y;
	cin>>w>>h;
	while(w!=0||h!=0){
		memset(map,0,sizeof(map));
		memset(N,0,sizeof(N));
		cin>>X>>Y;
		cin>>ga>>gb;
		cin>>n;
		for(i=0;i<n;i++){
			cin>>c>>d>>x>>y;
			if(d){
				map[y][x]=c;
				map[y+1][x]=c;
				map[y+2][x]=c;
				map[y+3][x]=c;
				map[y][x+1]=c;
				map[y+1][x+1]=c;
				map[y+2][x+1]=c;
				map[y+3][x+1]=c;

			}
			else{
				map[y][x]=c;
				map[y+1][x+1]=c;
				map[y+1][x+2]=c;
				map[y+1][x+3]=c;
				map[y+1][x]=c;
				map[y][x+1]=c;
				map[y][x+2]=c;
				map[y][x+3]=c;

			}
		}
		R=map[Y][X];
		if(R==map[gb][ga]){
			if(block(Y,X)) cout<<"OK"<<endl;
		        else cout<<"NG"<<endl;
		}
		else cout<<"NG"<<endl;
		//for(i=0;i<h;i++){
			//for(j=0;j<w;j++){
			//	cout<<map[i][j];
			//}
				
	//		cout<<endl;
		//}
		cin>>w>>h;
	}
	return 0;
}
bool block(int b,int a)
{
	//if(f==1) return 1;
	N[b][a]=1;
	if(ga==a&&gb==b) return 1;
	if(a+1!=w){
		if(map[b][a+1]==R&&N[b][a+1]==0) return block(b,a+1);}
	if(b+1!=h){
		if(map[b+1][a]==R&&N[b+1][a]==0) return block(b+1,a);}
	if(a-1!=-1){
		if(map[b][a-1]==R&&N[b][a-1]==0) return block(b,a-1);}
	if(b-1!=-1){
		if(map[b-1][a]==R&&N[b-1][a]==0) return block(b-1,a);}
	return 0;
}