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[101][101];
int xg, yg;
int w, h;
int col;
int dx[] = {0, 1, 0, -1};
int dy[] = {-1, 0, 1, 0};
bool flag;

void dfs(int x, int y)
{
    map[y][x] = 0;

    if (x == xg && y == yg) {
        flag = true;
        return ;
    }

    for (int i = 0; i < 4; i++) {
        int nx = x + dx[i];
        int ny = y + dy[i];
        
        if (nx < 0 || ny < 0 || nx >= w || ny >= h)
            continue;
        else if (map[ny][nx] == col)
            dfs(nx, ny);
    }
}

void setblock(int c, int d, int bx, int by)
{
    int wlim = 4, hlim = 2;

    if (d == 1) {
        wlim = 2;
        hlim = 4;
    }

    for (int y = 0; y < hlim; y++)
        for (int x = 0; x < wlim; x++)
            map[by + y][bx + x] = c;
}


int main()
{
    while (cin >> w >> h, w || h) {
        int xs, ys;
        int n;

        for (int y = 0; y < h; y++)
            for (int x = 0; x < w; x++)
                map[y][x] = 0;

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

        xs--, ys--, xg--, yg--;
        for (int i = 0; i < n; i++) {
            int c, d, x, y;
            
            cin >> c >> d >> x >> y;
            x--, y--;            
            setblock(c, d, x, y);
        }
        col = map[ys][xs];
        flag = false;
        if (col)
            dfs(xs, ys);

        if (flag)
            cout << "OK" << endl;
        else
            cout << "NG" << endl;
    }

    return 0;
}

C++: #include <iostream>
using namespace std;
int F[102][102];

void DFScolor(int X,int Y,int color){

	if(F[X][Y]!=color)
		return;
	
	F[X][Y]=9;
	DFScolor(X-1,Y,color);
	DFScolor(X,Y+1,color);
	DFScolor(X+1,Y,color);
	DFScolor(X,Y-1,color);
	
}


int main(){
while(1){
	int H,W,xg,yg,xs,ys,n,count=0;
	cin>>H;
	if(H==0)
		count++;
	cin>>W;
	if(W==0)
		count++;
	if(count==2)
		return 0;
	cin>>xs>>ys;
	cin>>xg>>yg;	
	cin>>n;
	int c,d,x,y;
	int xb[n],yb[n],colo[n];
	for(int i=0;i<n;i++){
		
		cin>>c>>d>>x>>y;
		colo[i]=c;
		xb[i]=x;
		yb[i]=y;
		if(d==0){
			for(int o=y;o<y+2;o++){
				for(int j=x;j<x+4;j++){
					F[j][o]=c;
				}
			}
		}
		else if(d==1){
			for(int o=y;o<y+4;o++){
				for(int j=x;j<x+2;j++){
					F[j][o]=c;
				}
			}
		}
		
	}
	
	for(int i=0;i<n;i++){
		if(xb[i]==xs&&yb[i]==ys){
			DFScolor(xb[i],yb[i],colo[i],xg,yg);
			
			break;
		}
	}
	if(F[xg][yg]==9)
		cout<<"OK"<<endl;
	else
		cout<<"NG"<<endl;
	
}
}

C++: #include<cstdio>
#include<cstring>
#include<iostream>

using namespace std ;

bool came[ 110 ][ 110 ] ;

int mx[] = { 1 ,0 ,0 ,-1 } ;
int my[] = { 0 ,1 ,-1 ,0 } ;

int w ,h ;
int gx ,gy ;

int ok_or_ng( int x ,int y )
{

	if( x == gx && y == gy )
		return 1 ;

	came[ y ][ x ] = false ;

	for( int i = 0 ; i < 4 ; i++ )
	{
		int xx = x + mx[ i ] ;
		int yy = y + my[ i ] ;
		if( xx > 0 && xx <= w && yy > 0 && yy <= h && came[ yy ][ xx ] )
			return ok_or_ng( xx ,yy ) ;
	}
	return 0 ;
}

void wide( int x ,int y ,int c ,int map[][ 110 ] )
{

	for( int i = 0 ; i < 2 ; i++ )
	{
		for( int j = 0 ; j < 4 ; j++ )
			map[ y + i ][ x + j ] = c ;
	}

	return ;
}

void high( int x ,int y ,int c ,int map[][ 110 ] )
{

	for( int i = 0 ; i < 4 ; i++ )
	{
		for( int j = 0 ; j < 2 ; j++ )
			map[ y + i ][ x + j ] = c ;
	}

	return ;
}

int main()
{
	while( cin >> w >> h )
	{
		if( w == h && w == 0 )
		return 0 ;

		memset( came ,false ,sizeof came ) ;
		int map[ 110 ][ 110 ] = { 0 } ;

		int sx ,sy ;

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

		int n ;
		cin >> n ;					// 0 w	1 h

		int c ,d ,x, y ;
		for( int i = 0 ; i < n ; i++ )
		{
			cin >> c >> d >> x >> y ;
			d ? high( x ,y ,c ,map ) : wide( x ,y ,c ,map ) ;
		}

		c = map[ gy ][ gx ] ;


		for( int i = 1 ; i <= h ; i++ )
		{
			for( int j = 1 ; j <= w ; j++ )
			{
				if( map[ i ][ j ] == c )
					came[ i ][ j ] = true ;
			}
		}

		if( map[ gy ][ gx ] == map[ sy ][ sx ] )
			ok_or_ng( sx ,sy ) ? printf( "OK\n" ) : printf( "NG\n" ) ;
		else
			printf( "NG\n" ) ;

		/*if( came[ gy ][ gx ] ){
		for( int i = 0 ; i <= h + 1 ; i++ )
		{
			for( int j = 0 ; j <= w + 1 ; j++ )
				cout << map[ i ][ j ] ;
			cout << endl ;
		}}*/
	}
}

C++: #include <iostream>
using namespace std;
  
int F[102][102];
int xg,yg,w,h;
  
  
void DFS(int Y,int X,int c){
  if(Y < 1 || X < 1)
    //return;
  if(F[Y][X] != c){
    return;
  }
  
  F[Y][X] = -1;
  DFS(Y+1,X  ,c);
  DFS(Y-1  ,X,c);
  DFS(Y,X+1  ,c);
  DFS(Y  ,X-1,c);
}
  
  
int main(){
  int xs,ys,n;
  while(1){
    cin >> w >> h;
    if(w == 0 && h == 0)
      break;
for(int i=0; i<102; i++){
      for(int j=0; j<102; j++){
        F[i][j] = 00;
      }
    }
      
    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 == 0){
        for(int j=0;j<4;j++){
          F[x+j][y] = c;
          F[x+j][y+1] = c;
        }
      } else {
        for(int j=0;j<4;j++){
          F[x][y+j] = c;
          F[x+1][y+j] = c;
        }
      }
    }
  DFS(xs,ys,F[xs][ys]);
  
  if(F[xg][yg] == -1){
    cout << "OK" << endl;
  } else {
    cout << "NG" <<endl;
  }
  }
}