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>
#include <vector>
#include <string>
#include <cmath>
#include <set>
#include <algorithm>
#include <array>
#include <complex>
#include <utility>
#include <map>
int needleX[4] = { -1,0,1,0 };
int needleY[4] = { 0,1,0,-1 };
bool dfs(int x, int y, int goalx, int goaly, std::vector<std::vector<bool>>&canGo) {
    if (x == goalx && y == goaly) { return true; }

    canGo[y][x] = false;
    for (int i = 0; i < 4; i++) {
        int next_x = x + needleX[i];
        int next_y = y + needleY[i];

        if (canGo[next_y][next_x]) {
            bool flag = dfs(next_x, next_y, goalx, goaly, canGo);
            if (flag)
                return true;
        }
    }
    return false;
}
int main(void) {
    int h, w, n;
    std::cin >> w >> h;
    std::vector<std::string> ans;
    while(h!=0&& w!=0){
        int color, orient, leftX, leftY;
        int sx, sy, gx, gy;
        std::cin >> sx >> sy >> gx >> gy;
        std::vector<std::vector<int>> board(h + 2, std::vector<int>(w+ 2, 0));
        std::vector<std::vector<bool>> canGo(h + 2, std::vector<bool>(w + 2, false));
        std::cin >> n;
        int start = 0, goal = 0;
        for (int i = 0; i < n; i++) {
            std::cin >> color >> orient >> leftX >> leftY;


            if (orient == 0) {
                for (int j = 0; j <= 3; j++) {
                    for (int k = 0; k <= 1; k++) {
                        board[leftY + k][leftX + j] = color;
                        if (leftX + j == sx && leftY + k == sy) {
                            start = color;
                        }
                        else if (leftX + j == gx && leftY + k == gy) {
                            goal = color;
                        }
                    }
                }

            }
            else {
                for (int j = 0; j <= 1; j++) {
                    for (int k = 0; k <= 3; k++) {
                        board[leftY + k][leftX + j] = color;
                        if (leftX + j == sx && leftY + k == sy) {
                            start = color;
                        }
                        else if (leftX + j == gx && leftY + k == gy) {
                            goal = color;
                        }
                    }
                }
            }
        }
        /*for (int i = 0; i <= w; i++) {
            for (int j = 0; j <= h; j++) {
                std::cout << board[i][j] << " ";
            }
            std::cout << std::endl;
        }*/
        if (start != goal) {
            ans.push_back("NG");
            
            break;
        }
        for (int i = 0; i <= w; i++) {
            for (int j = 0; j <= h; j++) {
                if (board[i][j] == start) {
                    canGo[i][j] = true;
                }
            }
        }
        bool result = dfs(sx, sy, gx, gy, canGo);
        if (result) { ans.push_back("OK"); }
        else { ans.push_back("NG"); }
        std::cin >> h >> w;
    }
    int anssize = ans.size();
    for (int i = 0; i < anssize; i++) {
        std::cout << ans[i] << std::endl;
    }
    return 0;
}

C++: #include <iostream>
using namespace std;

int C[102][102];
int ans;
int xg,yg;

void meiro(int W,int H,int c){
  if(W==xg && H==yg){
    ans = 1;
    return;
  }

  if(C[W][H]!=c){
    return;
  }

  C[W][H] = '.';

  meiro(W-1,H  ,c);
  meiro(W  ,H+1,c);
  meiro(W+1,H  ,c);
  meiro(W  ,H-1,c);
}

int main(){
  while(1){
    int w,h;
    cin >> w >> h;

    if(w==0 && h==0){
      break;
    }

    int xs,ys;
    cin >> xs >> ys;

    cin >> xg >> yg;

    int n;
    cin >> n;
    int c[n],d[n],x[n],y[n];

    int cbase;
    for(int i=0;i<w;i++){
      for(int j=0;j<h;j++){
        C[w][h] = 0;
      }
    }
    for(int i=0;i<n;i++){
      cin >> c[i] >> d[i] >> x[i] >> y[i];

      if(d[i]==0){
        for(int j=x[i];j<x[i]+4;j++){
          for(int k=y[i];k<y[i]+2;k++){
            C[j][k]=c[i];
          }
        }
      }
      if(d[i]==1){
        for(int j=x[i];j<x[i]+2;j++){
          for(int k=y[i];k<y[i]+4;k++){
            C[j][k]=c[i];
          }
        }
      }

      if(x[i]==xs &&y[i]==ys){
        cbase = c[i];
      }
    }
    ans = 0;
    meiro(xs,ys,C[xs][ys]);

    if(ans==1){
      cout << "OK" << endl;
    }else{
      cout << "NG" << endl;
    }
  }

  return 0;
}

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(ys+1,xs) + solve(ys,xs+1)+ solve(ys-1,xs) + solve(ys,xs-1);
}