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;

int map[102][102];

void route(int w, int h, int color) {
	if (map[w][h] != color)
		return;
	map[w][h] = 10;
	route(w, h + 1, color);
	route(w + 1, h, color);
	route(w, h - 1, color);
	route(w - 1, h, color);
}


int main() {
	int h, w, xs, ys, xg, yg, n;
	int c, d, x, y,color;

	while (1) {
		for (int i = 0; i < 102; i++)
			for (int j = 0; j < 102; j++)
				map[i][j] = 0;
		cin >> w >> h;		
		if (w == 0 && h == 0)
			break;

		cin>>xs >> ys >> xg >> yg >> n;

		for (int i = 0; i<n; i++) {
			cin >> c >> d >> x >> y;
			if (d == 0) {
				for (int j = 0; j < 4; j++)
					map[j + x][y] = map[j + x][y + 1] = c;
			}
			else {
				for (int j = 0; j < 4; j++)
					map[x][y + j] = map[x + 1][y + j] = c;
			}
		}

		color = map[xs][ys];
		route(xs, ys, color);
		
		if (map[xg][yg]==10)
			cout << "OK" << endl;
		else
			cout << "NG"<<endl;
	}

	return 0;
}

C++: #include <iostream>
using namespace std;
 
int weight, hight;
int g[101][101] = {0};
int sc;
int sx, sy, gx, gy;
bool flag = false;
const int vx[4] = {0, 0, 1, -1};
const int vy[4] = {1, -1, 0, 0};
 
void dfs(int x, int y){
    if(x == gx && y == gy){
        flag = true;
        return;
    }
    
    if(g[y][x] == 0){
        flag = false;
        return;
    }
    
    g[y][x] = -1;
    
    for(int i = 0;i < 4;i++){
        int nx = x + vx[i];
        int ny = y + vy[i];
         
        if(nx >= 0 && nx < weight && ny >= 0 && ny < hight && g[ny][nx] == sc){
            dfs(nx, ny);
        }
    }
    return;
}
 
int main(){
    while(1){
        int n, c, d, x, y;
        flag = false;
        g[101][101] = {0};
        
        cin >> weight >> hight;
        
        if(weight == 0 && hight == 0){
            break;
        }
         
        cin >> sx >> sy >> gx >> gy >> n;
        sx--; sy--; gx--; gy--;
         
        for(int i = 0;i < n;i++){
            cin >> c >> d >> x >> y;
            x--; y--;
             
            if(d == 0){
                for(int h = 0;h < 2;h++){
                    for(int w = 0;w < 4;w++){
                        g[y+h][x+w] = c;
                    }
                }
            }else{
                for(int h = 0;h < 4;h++){
                    for(int w = 0;w < 2;w++){
                        g[y+h][x+w] = c;
                    }
                }
            }
        }
         
        sc = g[sy][sx];
        dfs(sx, sy);
         
        if(flag){
            cout << "OK" << endl;
        }else{
            cout << "NG" << endl;
        }
    }
     
    return 0;
}

C++: #include <iostream>
using namespace std;
bool b=false;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};

void dfs(int a[][110] ,int x , int y , int w , int h , int xg , int yg , int c){
	if(x==xg&&y==yg) {b=true;return;}
	for(int i=0;i<4;++i){
		int tx=x+dx[i];
		int ty=y+dy[i];
		if(tx<=0||ty<=0||tx>w||ty>h) continue;
		if( a[tx][ty]!=c || a[tx][ty]==0) continue;
		if(b) continue;
		dfs( a,tx,ty,w,h,xg,yg,c);
	}
}
int main(){
	int w , h;
	while(cin >> w >> h , w||h){
		int xs , ys , xg , yg ;
		int n;
		b=false;
		int board[110][110]={0};
		cin >> xs >> ys >> xg >> yg >> n;
		for(int i=0;i<n;++i){
			int c , d , x , y;
			cin >> c >> d >> x >> y;
			if(!d){
				for(int k=y;k<y+2;++k){
					for(int j=x;j<x+4;++j){
						board[j][k]=c;
					}
				}
			} else {
				for(int k=y;k<y+4;++k){
					for(int j=x;j<x+2;++j){
						board[j][k]=c;
					}
				}
			}
		}
		int sc=board[xs][ys];
		int gc=board[xg][yg];
		if(sc!=gc) {
		}
		else dfs(board , xs , ys , w , h , xg , yg , sc);
		cout << ( b ? "OK" : "NG") << endl;
	}
	return 0;
}