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];
#define START 20

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

    if(Array[h][w] != c || Array[h][w] == 0 || Array[h][w] == 6){
      return;
    }

    int tmp=Array[h][w];

    Array[h][w] = 6;

    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;


      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;
            }
          }
        }
      }

      /*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(Array[Goal[0]][Goal[1]] == 6){
        cout << "OK" << endl;
      }
      else{
        cout << "NG" << endl;
      }

  }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std ;

#define pb(n) push_back(n)
#define fi first
#define se second
#define all(r) begin(r),end(r)
#define vmax(ary) *max_element(all(ary))
#define vmin(ary) *min_element(all(ary))
#define debug(x) cout<<#x<<": "<<x<<endl
#define fcout(n) cout<<fixed<<setprecision((n))
#define scout(n) cout<<setw(n)
#define vary(type,name,size,init) vector< type> name(size,init)
#define vvl(v,w,h,init) vector<vector<ll>> v(w,vector<ll>(h,init))
#define mp(a,b) make_pair(a,b)

#define rep(i,n) for(int i = 0; i < (int)(n);++i)
#define REP(i,a,b) for(int i = (a);i < (int)(b);++i)
#define repi(it,array) for(auto it = array.begin(),end = array.end(); it != end;++it)
#define repa(n,array) for(auto &n :(array))

using ll = long long;
using pii = pair<int,int> ;
using pll = pair<ll,ll> ;

const int mod = 1000000007;
constexpr ll inf = ((1<<30)-1)*2+1 ;
constexpr double PI = acos(-1.0) ;
double eps = 1e-10 ;
const int dy[] = {-1,0,1,0,1,-1,1,-1};
const int dx[] = {0,-1,0,1,1,-1,-1,1};

inline bool value(int x,int y,int w,int h){
  return (x >= 0 && x < w && y >= 0 && y < h);
}
int xs,ys,xg,yg,n;
ll w,h;
vector<vector<ll>> field;
vector<vector<ll>> f;
bool res = false;

void dfs(int x,int y,int c){
  if(f[x][y] != inf) return ;
  if(x == xg && y == yg){
    res = true;
    return ;
  }
  f[x][y] = 1;
  rep(i,4){
    int nx = x + dx[i],ny = y + dy[i];
    if(value(nx,ny,w,h) && field[nx][ny] == c){
      dfs(nx,ny,c);
    }
  }
  return ;
}

void solve(){
  f = vector<vector<ll>>(w+1,vector<ll>(h+1,inf));
  res = false;
  if(field[xs][ys]){
    dfs(xs,ys,field[xs][ys]);
  }
  if(res){
    cout << "OK" << endl;
    return ;
  }
  cout << "NG" << endl;
}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  while(cin >> w >> h && w+h){
    field = vector<vector<ll>>(w+1,vector<ll>(h+1,0));
    cin >> xs >> ys >> xg >> yg >> n;
    xs--,ys--,xg--,yg--;
    int c,d,x,y;
    rep(i,n){
      cin >> c >> d >> x >> y;
      --x,--y,--c;
      rep(j,2){
        rep(k,4){
          ll nx = k,ny = j;
          if(d){
            swap(nx,ny);
          }
          field[x+nx][y+ny] = c;
        }
      }
    }
    solve();
  }
  return 0;
}