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] == GOAL){
      is_goal = true;
      return;
    }

    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 <cmath>
#include <ctime>
#include <algorithm>
#include <iostream>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <list>
#include <deque>
#include <stack>
#include <bitset>
#include <functional>
#include <numeric>
#include <utility>
#include <iomanip>
#include <cstdio>
#include <cctype>
#include <queue>
#include <complex>
#include <climits>

typedef long long ll;

using namespace std;

int maze[110][110];
int f[110][110];
int w, h, xs, ys, xg, yg, res = 0;
int color;

void dfs(int cx, int cy){
	if(f[cx][cy]) return ;
	f[cx][cy] = 1;
	if(cx == xg && cy == yg){
		res = 1;
		return ;
	}
	for(int dx=-1; dx<=1; ++dx){
		for(int dy=-1; dy<=1; ++dy){
			if(abs(dx-dy) != 1) continue;
			int nx = cx + dx, ny = cy + dy;
			if(maze[nx][ny] == color){
				dfs(nx, ny);
			}
		}
	}
	return ;
}


int main(void){
	int n;
	while(cin >> w >> h){
		if(w == 0 && h == 0) break;
		cin >> xs >> ys >> xg >> yg >> n;
		for(int i=0; i<110; ++i){
			for(int j=0; j<110; ++j){
				maze[i][j] = 0;
				f[i][j] = 0;
			}
		}

		for(int i=0; i<n; ++i){
			int c, d, x, y;
			cin >> c >> d >> x >> y;
			if(d == 0){
				for(int j=y; j<=y+1; ++j){
					for(int k=x; k<=x+3; ++k){
						maze[j][k] = c;
					}
				}
			}
			if(d == 1){
				for(int j=y; j<=y+3; ++j){
					for(int k=x; k<=x+1; ++k){
						maze[j][k] = c;
					}
				}
			}
		}

		color = maze[xs][ys];
		if(color == 0){
			cout << "NG" << endl;
			continue;
		}

		dfs(xs, ys);

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

	return 0;
}

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

int board[100][100];
int xg , yg;
int w, h;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};
int sc;
bool b;

void dfs(int x , int y){
	if(x==xg&&y==yg) {b=true;return;}
	for(int i=0;i<4;++i){
		int tx=x+dx[i];
		int ty=y+dy[i];
		if(tx<0||ty<0||tx>=w||ty>=h) continue;
		if(board[tx][ty]!=sc|| board[tx][ty]==0) continue;
		if(b) continue;
		dfs(tx,ty);
	}
}

int main(){
	int xs , ys;
	int n;
	while(cin >> w >> h , w|h){
		b=false;
		memset(board,0,sizeof(board));
		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 k=0;k<2;++k){
					for(int j=0;j<4;++j){
						board[x+j][y+k]=c;
					}
				}
			} else {
				for(int k=0;k<4;++k){
					for(int j=0;j<2;++j){
						board[x+j][y+k]=c;
					}
				}
			}
		}
		sc=board[xs][ys];
		int gc=board[xg][yg];
		if(sc!=gc) {}
		else dfs(xs,ys);
		cout << ( b ? "OK" : "NG") << endl;
	}
	return 0;
}