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 Array[200][200];
bool is_goal = false;
#define START 20
#define GOAL 30

void DFS(int h,int w,int c){

  if(!is_goal){

    if(Array[h][w] == GOAL){
      is_goal = true;
      return;
    }

    if(Array[h][w] != c || Array[h][w] == 0){
      return;
    }

    int tmp=Array[h][w];

    Array[h][w] = 0;

    DFS(h-1,w,tmp);
    DFS(h,w+1,tmp);
    DFS(h+1,w,tmp);
    DFS(h,w-1,tmp);
  }

}

int main(){

    while(1){
      int H,W;
      int Start[2],Goal[2];
      int BlockNum;
      int color,dir,xpos,ypos;

      is_goal = false;

      for(int i=0;i<200;i++){
        for(int j=0;j<200;j++){
          Array[i][j] = 0;
        }
      }

      cin >> H >> W;

      if(H == 0 && W == 0){
        break;
      }

      cin >> Start[0] >> Start[1];

      cin >> Goal[0] >> Goal[1];

      cin >> BlockNum;

      for(int i=0;i<BlockNum;i++){
        cin >> color >> dir >> xpos >> ypos;
        for(int i=0;i<4;i++){
          for(int j=0;j<2;j++){
            if(!dir){//?¨?
              Array[xpos+i][ypos+j] = color;
            }
            else{
              Array[xpos+j][ypos+i] = color;
            }
          }
        }
      }
      Array[Goal[0]][Goal[1]] = GOAL;
      /*for(int i=1;i<=H;i++){
        for(int j=1;j<=W;j++){
          cout << Array[i][j];
        }
        cout << endl;
      }*/
      if(Array[Start[0]][Start[1]] != 0){
        DFS(Start[0],Start[1],Array[Start[0]][Start[1]]);
      }
      if(is_goal){
        cout << "OK" << endl;
      }
      else{
        cout << "NG" << endl;
      }

  }
    return 0;
}

C++: #include<stdio.h>
int a[103][103],gx,gy;
bool f(int sx,int sy,int c)
{
	if(sx==gx&&sy==gy)return true;
	if(a[sy][sx]!=c)return false;
	a[sy][sx]=0;
	if(f(sx+1,sy,c)||f(sx-1,sy,c)||f(sx,sy+1,c)||f(sx,sy-1,c))return true;
	return false;
}
int main()
{
	int h,w,sx,sy,n,i,j,c,d,x,y,
		dx[2][8]={{0,1,2,3,0,1,2,3},{0,0,0,0,1,1,1,1}},
		dy[2][8]={{0,0,0,0,1,1,1,1},{0,1,2,3,0,1,2,3}};
	while(scanf("%d%d",&w,&h),h)
	{
		scanf("%d%d%d%d%d",&sx,&sy,&gx,&gy,&n);
		for(i=0;i<103;++i)for(j=0;j<103;++j)a[i][j]=0;
		while(n--)
		{
			scanf("%d%d%d%d",&c,&d,&x,&y);
			for(i=0;i<8;++i) a[y+dy[d][i]][x+dx[d][i]]=c;
		}
		if(a[sy][sx]&&f(sx,sy,a[sy][sx]))puts("OK");
		else puts("NG");
	}
	return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<string>
	using namespace std;
	int xs,ys,w,h,n,ban[111][111],xg,yg;bool visited[101][101];
	bool dfs(int x,int y,int c){
		//cout<<x<<" "<<y<<endl;
		if(xg==x&&yg==y)return true;
		if(c-1||ban[x][y]!=c)return false;
		//if(ban[xs][ys]==0)return false;
		if(ban[x+1][y]==ban[xs][ys]&&visited[x][y]==false){
			visited[x][y]=true;
			if(dfs(x+1,y,c))return true;
		}
		if(ban[x][y+1]==ban[xs][ys]&&visited[x][y]==false){
			visited[x][y]=true;
			if(dfs(x,y+1,c))return true;
		}
		if(x>=2&&ban[x-1][y]==ban[xs][ys]&&visited[x][y]==false){
			visited[x][y]=true;
			if(dfs(x-1,y,c))return true;
		}
		if(y>=2&&ban[x][y-1]==ban[xs][ys]&&visited[x][y]==false){
			visited[x][y]=true;
			if(dfs(x,y-1,c))return true;
		}
		return false;
	}


int main(){

	while(cin>>w>>h&&w&&h){
	cin>>xs>>ys>>xg>>yg>>n;
	for(int i=0;i<101;i++)
	for(int j=0;j<101;j++)ban[i][j]=-1,visited[i][j]=false;
	
	for(int i=0;i<n;i++){
		int c,d,x,y;
		cin>>c>>d>>x>>y;
		if(!d){
			for(int i=x;i<x+4;i++){
				for(int j=y;j<y+2;j++){
					ban[i][j]=c;
				}
			}
		}
		else{
		for(int i=x;i<x+2;i++){
				for(int j=y;j<y+4;j++){
					ban[i][j]=c;
				}
			}
		}
		}
		if(dfs(xs,ys,ban[xs][ys]))cout<<"OK"<<endl;
	else cout<<"NG"<<endl;
	}
	return 0;
	}

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] = 10;
      }
    }
      
    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;
  }
  }
}