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 <cstdio>

using namespace std;

int field[102][102];
bool visited[102][102];
int w, h;
int xs, ys;
int xg, yg;
int n;
int d_x[] = {1, 0, -1, 0};
int d_y[] = {0, -1, 0, 1};

bool search(int y, int x) {
  if (visited[y][x] || field[y][x] == 0) {return false;}  
  if (y == yg && x == xg) {
    return true;
  }
  visited[y][x] = true;
  for (int i = 0; i < 4; i++) {
    if (search(y + d_y[i], x + d_x[i])) {return true;}
  }
  return false;
}

int main()
{
  while (true) {
    scanf("%d %d ", &w, &h);
    if (w == 0 && h == 0) {
      break;
    }
    scanf("%d %d ", &xs, &ys);
    scanf("%d %d ", &xg, &yg);
    scanf("%d ", &n);
    for (int i = 0; i < 102; i++) {
      fill(field[i], &field[i][102], 0);
      fill(visited[i], &visited[i][102], false);
    }
    for (int i = 0; i < n; i++) {
      int c, d, x, y;
      scanf("%d %d %d %d ", &c, &d, &x, &y);
      for (int i = 0; i < 2; i++) {
	for (int j = 0; j < 4; j++) {
	  if (d == 0) {
	    field[y + i][x + j] = c;
	  } else {
	    field[y + j][x + i] = c;
	  }
	}
      }
    }
    /*for (int i = 1; i <= h; i++) {
      for (int j = 1; j <= w; j++) {
	printf("%d ", field[i][j]);
      }
      printf("\n");
      }*/
    if (search(ys, xs)) {cout << "OK" << endl;}
    else {cout << "NG" << endl;}
  }
  return 0;
}

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

int ac,w,h,sx,sy,gx,gy,mp[100][100],vx[4]={1,0,-1,0},vy[4]={0,1,0,-1};

int check(int x,int y) {
	int i;
	mp[y][x]=-1;
	if (x==gx && y==gy) return 1;
	for (i=0;i<4;i++) {
		if (x+vx[i]>=0 && x+vx[i]<w && y+vy[i]>=0 && y+vy[i]<h) {
			if (mp[y+vy[i]][x+vx[i]]==ac) {if (check(x+vx[i],y+vy[i])==1) return 1;}
		}
	}
	return 0;
} 

int main() {
	int i,j,k,n,c,d,x,y;
	while(cin >> w >>  h) {
		if (w==0) break;
	for (i=0;i<h;i++) for (j=0;j<w;j++) mp[i][j]=0;	
	cin >> sx >> sy; 
	cin >> gx >> gy;
	sx--; sy--; gx--; gy--;
	cin >> n;
	for (k=0;k<n;k++) {
		cin >> c >> d >> x >> y;
		for (i=0;i<d*2+2;i++) for (j=0;j<4-d*2;j++) mp[y+i-1][x+j-1]=c;
		}
	ac=mp[sy][sx];
	if (mp[gy][gx]!=ac || ac==0) cout << "NG";  else { if (check(sx,sy)==1) cout << "OK"; else cout << "NG";}
	cout << endl;
	}  
	return 0;
}

C++: #include<iostream>
#include<queue>
#include<cstring>

void putblock(int x,int y,int c,int d);
bool bfs(std::pair<int,int> start,std::pair<int,int> goal);

std::queue< std::pair<int,int> > que;
int board[102][102];
bool visited[102][102];

int main()
{
	int n,w,h,x,y,c,d,xs,ys,xg,yg;
	
	while(1)
	{
		while(!que.empty()){que.pop();}
		memset(board,0,sizeof(board));
		memset(visited,0,sizeof(visited));
		std::cin>>w>>h;
		if(w==0&&h==0)break;
		std::cin>>xs>>ys>>xg>>yg>>n;
		for(int i=0;i<n;i++)
		{
			std::cin>>c>>d>>x>>y;
			putblock(x,y,c,d);
		}
		if(bfs(std::pair<int,int>(xs,ys),std::pair<int,int>(xg,yg)))
		{
			std::cout<<"OK"<<std::endl;
		}
		else
		{
			std::cout<<"NG"<<std::endl;
		}
	}
	return 0;
}

void putblock(int x,int y,int c,int d)
{
	int h,w;
	if(d==0)
	{
		h=2;
		w=4;
	}
	else
	{
		h=4;
		w=2;
	}
	for(int i=y;i<y+h;i++)
	{
		for(int j=x;j<x+w;j++)
		{
			board[i][j]=c;
		}
	}
}

bool bfs(std::pair<int,int> start,std::pair<int,int> goal)
{
	int x,y;
	if(board[start.second][start.first]==0||board[goal.second][goal.first]==0)return false;
	que.push(start);
	while(!que.empty())
	{
		que.pop();
		x=que.front().first;
		y=que.front().second;
		
		if(!visited[y][x])
		{
			visited[y][x]=true;
			if(board[y-1][x]==board[y][x])que.push(std::pair<int,int>(x-1,y));
			if(board[y+1][x]==board[y][x])que.push(std::pair<int,int>(x+1,y));
			if(board[y][x-1]==board[y][x])que.push(std::pair<int,int>(x,y-1));
			if(board[y][x+1]==board[y][x])que.push(std::pair<int,int>(x,y+1));

			if(x==goal.first&&y==goal.second)
			{
				return true;
			}
		}
	}
	return false;
}

C++: #include <iostream>
using namespace std;
 
int C[102][102];
 
void meiro(int W,int H,int c){
  if(C[W][H]!=c){
    return;
  }
 
  C[W][H] = -1;
 
  meiro(W+1,H  ,c);
  meiro(W-1  ,H,c);
  meiro(W,H+1 ,c);
  meiro(W  ,H-1,c);
}
 
int main(){
  while(1){
    int w,h;
    cin >> w >> h;
    if(w==0 && h==0){
      break;
    }
 
    for(int i=0;i<102;i++){
      for(int j=0;j<102;j++){
        C[i][j] = 10;
      }
    }
 
    int xs,ys,xg,yg;
    cin >> xs >> ys >> xg >> yg;
 
    int n;
    cin >> n;
 
    int c,d,x,y;
    for(int i=0;i<n;i++){
      cin >> c >> d >> x >> y;
 
      if(d==0){
        for(int j=x;j<x+4;j++){
          for(int k=y;k<y+2;k++){
            C[j][k]=c;
          }
        }
      }else{
        for(int j=x;j<x+2;j++){
          for(int k=y;k<y+4;k++){
            C[j][k]=c;
          }
        }
      }
    }
 
    meiro(xs,ys,C[xs][ys]);
 
    if(C[xg][yg] == -1){
      cout << "OK" << endl;
    }else{
      cout << "NG" << endl;
    }
  }
 
  return 0;
}

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

bool dfs(int x,int y);
int w,h;
int xs,ys;
int xg,yg;
int board[111][111];
int cheak[111][111];
int xd[]={0,-1,0,1};
int yd[]={-1,0,1,0};
int main(){
  int n;
  int c,d,x,y;
  int a[]={1,0,1,0,1,0,1};
  int b[]={0,1,1,2,2,3,3};
  while(1){
    cin >> w >> h;
    if(w==0 && h==0) break;
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	board[i][j]=0;
	cheak[i][j]=0;
      }
    }
    cin >> xs >> ys;
    cin >> xg >> yg;
    cin >> n;
    for(int i=0;i<n;i++){
      cin >> c >> d >> x >> y;
      board[y-1][x-1]=c;
      for(int j=0;j<7;j++){
	if(d==0) board[y+a[j]-1][x+b[j]-1]=c;
	else board[y+b[j]-1][x+a[j]-1]=c;
      }
    }
    if(dfs(xs-1,ys-1)==true) cout << "OK" << endl;
    else cout << "NG" << endl;
  }
}

bool dfs(int x,int y){
  cheak[y][x]=1;
  if(x==xg-1 && y==yg-1) return true;
  for(int i=0;i<4;i++){
    int xn=x+xd[i];
    int yn=y+yd[i];
    if(xn>=0 && xn<w && yn>=0 && yn<h && board[yn][xn]==board[ys][xs] && cheak[yn][xn]==0){
      if(dfs(xn,yn)==true) return true;
    }
  }
  return false;
}