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;

class Solve{
private:
    int board[110][110];
    int board_weight;
    int board_hight;
    int start_x;
    int start_y;
    int goal_x;
    int goal_y;
    int start_color;
    const int vector_x[4] = {0, 0, -1, 1};
    const int vector_y[4] = {1, -1, 0, 0};
    bool flag = false;
    void dfs(int x, int y);
public:
    Solve(int Board_Weight, int Board_Hight, int Start_X, int Start_Y, int Goal_X, int Goal_Y);
    void set_Block(int Color, int Direction, int X, int Y);
    bool check();
};

Solve::Solve(int Board_Weight, int Board_Hight, int Start_X, int Start_Y, int Goal_X, int Goal_Y){
    board_weight = Board_Weight - 1;
    board_hight  = Board_Hight  - 1;
    start_x      = Start_X - 1;
    start_y      = Start_Y - 1;
    goal_x       = Goal_X - 1;
    goal_y       = Goal_Y - 1;
}
void Solve::set_Block(int Color, int Direction, int X, int Y){
    X -= 1; Y -= 1;
    if(X == start_x && Y == start_y){
        start_color = Color;
    }
    if(Direction == 0){
        for(int h = 0;h < 2;h++){
            for(int w = 0;w < 4;w++){
                board[Y+h][X+w] = Color;
            }
        }
    }else{
        for(int h = 0;h < 4;h++){
            for(int w = 0;w < 2;w++){
                board[Y+h][X+w] = Color;
            }
        }
    }
}
bool Solve::check(){
    Solve::dfs(start_x, start_y);
    return flag;
}

void Solve::dfs(int X, int Y){
    if(X == goal_x && Y == goal_y){
        flag = true;
        return;
    }
    
    for(int y = 0;y < 4;y++){
        for(int x = 0;x < 4;x++){
            int new_x = X + vector_x[x];
            int new_y = Y + vector_y[y];
            
            if(new_x >= 0 && new_x < board_weight){
                if(new_y >= 0 && new_y < board_hight){
                    if(start_color == board[new_y][new_x]){
                        board[Y][X] = 9;
                        dfs(new_x, new_y);
                    }
                }
            }
        }
    }
    return;
}

int main()
{
    while(true){
        int w, h, sx, sy, gx, gy, n, c, d, x, y;
        
        cin >> w >> h;
        if(w != 0 && h != 0){
            cin >> sx >> sy >> gx >> gy;
            
            Solve s(w, h, sx, sy, gx, gy);
            
            cin >> n;
            
            for(int i = 0;i < n;i++){
                cin >> c >> d >> x >> y;
                s.set_Block(c, d, x, y);
            }
            
            if(s.check() == true){
                cout << "OK\n";
            }else{
                cout << "NG\n";
            }
        }else{
            break;
        }
    }
    
    return 0;
}

C++: #include<iostream>
#include<map>
using namespace std;

bool dfs(int x,int y);
int w,h;
int xs,ys;
int xg,yg;
int board[111][111];
int cheak[111][111];
int xd[]={0,-1,0,1};
int yd[]={-1,0,1,0};
int main(){
  int n;
  int c,d,x,y;
  int a[]={1,0,1,0,1,0,1};
  int b[]={0,1,1,2,2,3,3};
  while(1){
    cin >> w >> h;
    if(w==0 && h==0) break;
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	board[i][j]=0;
	cheak[i][j]=0;
	cout << board[i][j];
      }
      cout << endl;
    }
    cin >> xs >> ys;
    cin >> xg >> yg;
    cin >> n;
    for(int i=0;i<n;i++){
      cin >> c >> d >> x >> y;
      board[y-1][x-1]=c;
      for(int j=0;j<7;j++){
	if(d==0) board[y+a[j]-1][x+b[j]-1]=c;
	else board[y+b[j]-1][x+a[j]-1]=c;
      }
    }
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	cout << board[i][j];
      }
      cout << endl;
    }
    if(dfs(xs-1,ys-1)==true) cout << "OK" << endl;
    else cout << "NG" << endl;
  }
}

bool dfs(int x,int y){
  cheak[y][x]=1;
  if(x==xg-1 && y==yg-1) return true;
  for(int i=0;i<4;i++){
    int xn=x+xd[i];
    int yn=y+yd[i];
    if(x>=0 && x<w && y>=0 && y<h && board[yn][xn]==board[ys][xs] && cheak[yn][xn]==0){
      if(dfs(xn,yn)==true) return true;
    }
  }
  return false;
}

C++: #include <iostream>
#include <string>
#include <queue>
using namespace std;

typedef pair<int, int> P;


int w, h;
int xs, ys, xg, yg, n, c, d, x, y;
int dx[] = {1, 0, -1, 0}, dy[] = {0, 1, 0, -1};

void put_b(int a[][105]) {
  int X, Y;
  if(d == 0) X = 4, Y = 2;
  else X = 2, Y = 4 ;
  for(int i = 0; i < Y; i++)
    for(int j = 0; j < X; j++)
      a[y + i][x + j] = c;
}

bool bfs(int a[][105]) {
  int cs = a[ys][xs];
  if(cs != a[yg][xg]) return false;

  cout << ys << xs << endl;
  queue<P> que;
  que.push(P(xs, ys));
  while(que.size()) {
    P p = que.front();
    que.pop();
    if(p.first == xg && p.second == yg) return true;
    for(int i = 0; i < 4; i++) {
      int nx = p.first + dx[i], ny = p.second +dy[i];
      if(0 < nx && nx <= w && 0 < ny && ny <= h && a[ny][nx] == cs) {
	que.push(P(nx, ny));
	a[ny][nx] = 0;
      }
    }
  }
  return false;
}
int main() {
  while(cin >> w >> h, w != 0 || h != 0) {
    int a[105][105] = {};
    cin >> xs >> ys;
    cin >> xg >> yg;
    cin >> n;
  
    while(n--) {
      cin >> c >> d >> x >> y;
      put_b(a);
    }
    
    /*  for(int i = 0; i < h; i++){
      for(int j = 0; j < w; j++)
      cout << a[i][j];
      cout << endl;
      }*/
    if(bfs(a) == true) cout << "OK" << endl;
    else cout << "NG" << endl;
  }
  return 0;
}