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 <stdio.h>
#include <iostream>
#include <math.h>
#include <numeric>
#include <vector>
#include <map>
#include <functional>
#include <stdio.h>
#include <array>
#include <algorithm>
#include <string>
#include <assert.h>
#include <stdio.h>
#include <queue>
#include<iomanip>
#include<bitset>
#include<list>
using namespace std;

const int mod = 1000000007;

struct Mod {
	int num;
	Mod() : num(0) { ; }
	Mod(int n) : num((n % mod + mod) % mod) { ; }
	operator int() { return num; }
};

Mod operator+(Mod a, Mod b) { return Mod((a.num + b.num) % mod); }
Mod operator-(Mod a, Mod b) { return Mod((mod + a.num - b.num) % mod); }
Mod operator*(Mod a, Mod b) { return Mod(((long long)a.num * b.num) % mod); }
Mod operator+=(Mod &a, Mod b) { return a = a + b; }
Mod operator-=(Mod &a, Mod b) { return a = a - b; }
Mod operator*=(Mod &a, Mod b) { return a = a * b; }
Mod operator^(Mod a, int n) {
	if (n == 0) return Mod(1);
	Mod res = (a * a) ^ (n / 2);
	if (n % 2) res = res * a;
	return res;
}
Mod inv(Mod a) { return a ^ (mod - 2); }
Mod operator/(Mod a, Mod b) { 
assert(b!=0);
return a * inv(b);
 }

#define MAX_N 1024000

Mod fact[MAX_N], factinv[MAX_N];
void init() {
	fact[0] = Mod(1); factinv[0] = 1;
	for (int i = 0; i < MAX_N - 1; ++i) {
		fact[i + 1] = fact[i] * Mod(i + 1);
		factinv[i + 1] = factinv[i] / Mod(i + 1);
	}
}
Mod comb(int a, int b) {
	return fact[a] * factinv[b] * factinv[a - b];
}

#define REP(i,n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()


int dx[4] = { -1,0,1,0 };
int dy[4] = { 0,-1,0,1 };
struct Node {
	Node(int a, int b, int c) {
		atime = a;
		x = b;
		y = c;
	}
	int atime;
	int x;
	int y;
};
class Compare {
public:
	bool operator()(const Node& l, const Node& r) {
		return l.atime < r.atime;
	}
};


int main() {
	while(1) {
		int w, h;
		cin >> w >> h;
		if (!w)return 0;
		vector<vector<int>> maze(h+2, vector<int>(w+2,0));

		int xs, ys, xg, yg;
		cin >> xs >> ys >> xg >> yg;
		int n;
		cin >> n;
		for (int i = 0; i < n; ++i) {
			int c, d, x, y;
			cin >> c >> d >> x >> y;
			if (!d) {
				for (int ax = 0; ax < 4; ++ax) {
					for (int ay = 0; ay < 2; ++ay) {
						maze[y+ay][x+ax] = c;
					}
				}
			}
			else {
				for (int ax = 0; ax < 2; ++ax) {
					for (int ay = 0; ay < 4; ++ay) {
						maze[y + ay][x + ax] = c;
					}
				}
			}
		}
		/*for (int i = 0; i < maze.size(); ++i) {
			for (int j = 0; j < maze[0].size(); ++j) {
				cout << maze[i][j];
			}
			cout << endl;
		}*/
		int color = maze[ys][xs];
		if (!color||color!=maze[yg][xg]) {
			cout << "NG" << endl;
			continue;
		}
		
		vector<vector<bool>>times(h+2 , vector<bool>(w+2, false));

		priority_queue<Node,vector<Node>,Compare> qu;
		 qu.emplace(0,xs,ys);
		 bool flag=false;
		while (!qu.empty()) {
			Node an(qu.top());
			qu.pop();
			if (an.x == xg&&an.y == yg) {
				flag = true;
				break;
			}
			else {
				for (int i = 0; i < 4; ++i) {
					if (maze[an.y + dy[i]][an.x + dx[i]] == color) {
						if (times[an.y + dy[i]][an.x + dx[i]]) {

						}
						else {
							qu.push(Node{ an.atime + 1,an.x + dx[i], an.y + dy[i] });
							times[an.y + dy[i]][an.x + dx[i]] = true;
						}
						
					}
				}
			}
		}
		if (flag) {
			cout << "OK" << endl;

		}
		else {
			cout << "NG" << endl;
		}
	}
	return 0;

}

C++: #include<map>
#include<queue>
#include<cstdio>
#include<cstring>
#include<stdio.h>
#include<iostream>
#include<algorithm>
#define SIZE 110
using namespace std;

typedef pair<int,int> P;

void solve(void);       //処理

int n;             //ブロックの個数
int w,h;           //ボードの幅、高さ
int goal;          //迷路になっているか
int scolor;        //スタート位置の色
int sx,sy,gx,gy;   //スタートの座標、ゴールの座標
int mass[SIZE][SIZE];
int data[SIZE][SIZE];
int dx[4]={1,0,-1,0};
int dy[4]={0,1,0,-1};
int c[SIZE],d[SIZE],x[SIZE],y[SIZE];       //ブロックの色、向き、左上の座標


int main(){

  int i,j;             //カウンタ変数

  while(1){

    goal=0;

    /*情報の入力*/
    cin>>w>>h;

    if(w==0 && h==0)break;
    
    cin>>sx>>sy;
    cin>>gx>>gy;  
    cin>>n;
    
    for(i=0;i<n;i++){
      cin>>c[i]>>d[i]>>x[i]>>y[i];
      
    }

  memset(mass,0,sizeof(mass));

  /*マスの作成*/
  for(i=0;i<n;i++){
    if(d[i]==0){       //横向きなら
      for(j=0;j<4;j++){
	mass[y[i]][x[i]+j]=c[i];
	mass[y[i]+1][x[i]+j]=c[i];
      }
    }
    else if(d[i]==1){              //縦向きなら
      for(j=0;j<4;j++){
	mass[y[i]+j][x[i]]=c[i];
	mass[y[i]+j][x[i]+1]=c[i];
      }
    }
  }
  
  scolor=mass[sy][sx];

  if(gx==sx && gy==sy)cout<<"OK"<<endl;

  else if(scolor==mass[gy][gx]){
  
    solve();
    
    if(goal==1){
      cout<<"OK"<<endl;
    } else {
      cout<<"NG"<<endl;
    }
  }
  else {
    cout<<"NG"<<endl;
  }

  }
  
  return 0;
}
void solve(void){
  
  int i,j;
  queue<P> que;
  memset(data,-1,sizeof(data));
  que.push(P(sy,sx));     //queにスタート位置の座標を格納
  data[sy][sx]=0;
  
  while(!que.empty()){    //queが空でない間
    P p=que.front();
    que.pop();
    
    if(p.first==gy && p.second==gx){
      goal=1;
      break;
    }
    for(i=0;i<4;i++){
      int ny=p.first+dy[i];
      int nx=p.second+dx[i];
      if(nx>=0 && nx<w && ny>=0 && ny<h && mass[ny][nx]==scolor && data[ny][nx]==-1){
	que.push(P(ny,nx));
	data[ny][nx]=1;
      }
    }
  }
  return;
}