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<bits/stdc++.h>
using namespace std;
#define ANSWER(x) cout<<x<<endl
#define debug(x) cout<<#x<<": "<<x
const int BA = 1000;
const int INFTY = (1<<21);
int xg,yg,w,h,gc;
int maps[101][101];
int solve(int xs,int ys);
int main(){
  int tate[2] = {2,4};
  int yoko[2] = {4,2};
  int xs,ys,n;
  int c[101],d[101],x[101],y[101];
  while(1){
    fill(maps[0],maps[101],0);
    cin >> w >> h;
    if(w==0 && h==0)break;
    cin >> xs >> ys >> xg >> yg >> n;
    for(int i=0;i<n;i++){
      cin >> c[i] >> d[i] >> x[i] >> y[i];
    }
    for(int i=0;i<n;i++){
      for(int j=y[i];j<y[i]+tate[d[i]];j++){
	for(int k=x[i];k<x[i]+yoko[d[i]];k++){
	  if(j == ys && k == xs)gc = c[i];
	  maps[j-1][k-1] = c[i];
	}
      }
    }
    /* for(int i=0;i<h;i++){
       for(int j=0;j<w;j++){
       cout << maps[i][j];
       }
       cout << endl;
       }*///マップ確認用
    if(solve(ys-1,xs-1))cout << "OK\n";
    else cout << "NG\n";
  }
}
int solve(int ys,int xs){
  if(xs < 0 || ys < 0 || xs > w-1 || ys > h-1 || maps[ys][xs] == 0){
    return 0;
  }
  else if(maps[ys][xs] == maps[xg-1][yg-1]){
    return 1;
  }
  maps[ys][xs] = 0;
  return solve(xs+1,ys) + solve(xs,ys+1)+ solve(xs-1,ys) + solve(xs,ys-1);
}

C++: #include <iostream>
#include <cstdio>
#include <string>
#include <sstream>
#include <algorithm>
#include <math.h>
#include <map>
#include <iomanip>
#include <vector>

using namespace std;



int w, h, xs, ys, xg, yg, n, c, d, x, y, newc;
int board[100][100];	//添字は行、列の順
int dirx[] = {-1, 0, 0, 1};
int diry[] = {0, -1, 1, 0};
//xs,ysから接する同じ色のところを100に置き換えていく
void dfs(int x, int y)
{
	board[y][x] = 6;
	
	for (int i=0; i<4; i++)
	{
		int nx, ny;
		
		nx = x + dirx[i];
		ny = y + diry[i];
		
		if (0<=nx && nx<w && 0<=ny && ny<h && board[ny][nx]==newc)
		{
			dfs(nx, ny);
		}
	}
}


int main()
{
	while (cin >> w >> h)
	{
		if (w == 0 && h == 0) break;
		
		cin >> xs >> ys >> xg >> yg >> n;
		
		//board初期化
		for (int i=0; i<h; i++)
		{
			for (int j=0; j<w; j++)
			{
				board[i][j] = 0;
			}
		}
		
		for (int i=0; i<n; i++)
		{
			cin >> c >> d >> x >> y;
			if (d == 0)
			{
				//横向き
				board[y-1][x-1] = board[y-1][x] = board[y-1][x+1] = board[y-1][x+2] = c;
				board[y][x-1] = board[y][x] = board[y][x+1] = board[y][x+2] = c;
			} else {
				//縦向き
				board[y-1][x-1] = board[y][x-1] = board[y+1][x-1] = board[y+2][x-1] = c;
				board[y-1][x] = board[y][x] = board[y+1][x] = board[y+2][x] = c;
			}
		}
		
		newc = board[ys-1][xs-1];
		dfs(xs-1, ys-1);
		if (board[yg-1][xg-1] == 6)
		{
			cout << "OK" << endl;
		} else {
			cout << "NG" << endl;
		}
		
		
		//テスト出力
		/*
		for (int i=0; i<h; i++)
		{
			for (int j=0; j<w; j++)
			{
				cout << board[i][j];
			}
			cout << endl;
		}
		*/
	}
	
	return 0;
}

C++: #include <iostream>
#include<queue>
#include<string.h>
using namespace std;
#define TATE 1
#define YOKO 0
int main(void){
    int map[101][101];
    int board[101][101];
    int T[]={0,-1,1,0};
    int Y[]={1,0,0,-1};
    int w,h,xs,xg,ys,yg,n,color,muki,x,y;
    struct ST {
        int x;
        int y;
    };
    ST RE;
    ST GO;
    queue<ST> Q;
    while(1){
        memset(map,0,sizeof(map));
        memset(board,0,sizeof(board));
        cin>>w>>h;
        if(w==0&&h==0)break;
        cin>>xs>>ys>>xg>>yg>>n;
        for(int i=0;i<n;i++){
            cin>>color>>muki>>x>>y;
            if(muki==YOKO){
                for(int j=0;j<4;j++){
                    board[y][x+j]=board[y+1][x+j]=color;
                }
            }
            else{
                for(int j=0;j<4;j++){
                    board[y+j][x]=board[y+j][x+1]=color;
                }
            }
        }
       /* for(int i=1;i<=h;i++){
            for(int j=1;j<=w;j++){
                cout<<board[i][j];
            }
            cout<<endl;
        }*/
        RE.x=xs;
        RE.y=ys;
        map[ys][xs]=1;
        Q.push(RE);
        int flag=0;
        while(!Q.empty()){
            RE=Q.front();
            Q.pop();
            if(RE.x==xg&&RE.y==yg&&board[RE.y][RE.x]==board[yg][xg]){
                flag=1;
                //cout<<RE.x<<" "<<RE.y<<endl;
                break;
            }
            else{
                for(int i=0;i<4;i++){
                    GO=RE;
                    if(GO.x+Y[i]>0&&GO.y+T[i]>0&&GO.x+Y[i]<101&&GO.y+T[i]<101&&board[GO.y+T[i]][GO.x+Y[i]]==board[yg][xg]&&map[GO.y+T[i]][GO.x+Y[i]]!=1){
                        GO.x+=Y[i];
                        GO.y+=T[i];
                        map[GO.y][GO.x]=1;
                        Q.push(GO);
                    }
                }
            }
        }
       /* for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                cout<<board[i][j];
            }
            cout<<endl;
        }*/
        if(flag==1){
            cout<<"OK"<<endl;
        }
        else{
            cout<<"NG"<<endl;
        }
    }
    
}