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;
 
char F[102][102];
 
void DFS(int Y,int X,char c){
  if(F[Y][X]!=c){
    return;
  }
 
  F[Y][X] = '0';
 
  DFS(Y-1,X  ,c);
  //DFS(Y-1,X+1,c);
  DFS(Y  ,X+1,c);
  //DFS(Y+1,X+1,c);
  DFS(Y+1,X  ,c);
  //DFS(Y+1,X-1,c);
  DFS(Y  ,X-1,c);
  //DFS(Y-1,X-1,c);
}
 
int main(){
  while(1){
  int N,M;
  cin >> N >> M;
  if(N==0&&M==0)
    break;
 
  for(int h=1;h<=N;h++){
    for(int w=1;w<=M;w++){
      cin>>F[h][w];
    }
  }
 
  int cnt=0;
  for(int h=1;h<=N;h++){
    for(int w=1;w<=M;w++){
      if(F[h][w]=='@'){
        cnt++;
        DFS(h,w,'@');
      }else if(F[h][w]=='#'){
        cnt++;
        DFS(h,w,'#');
      }else if(F[h][w]=='*'){
          cnt++;
          DFS(h,w,'*');
      }
    }
  }
  cout<<cnt<<endl;
}
  return 0;
}

C++: #include <iostream>
#include <math.h>
#include <algorithm>
using namespace std;

class Point
{
public:
	int x;
	int y;

	Point(int x = 0, int y = 0) : x(x), y(y){}
	bool operator == (const Point& target)
	{
		return (this->x == target.x && this->y == target.y);
	}
};

int w, h;
int map[105][105];
Point start;
Point goal;
int n; //????????????????????°
int c; //???
int d; //??????
Point blockPoint;

void setSideways(const Point& blockPoint)
{
	//?¨??????????????????????map???????????????????????????
	//
	//	????????????	(?????????blockPoint?????????)
	//	????????????
	for (int i = 0; i < 4; ++i)
	{
		for (int j = 0; j < 2; ++j)
		{
			map[blockPoint.x + i][blockPoint.y + j] = c;
		}
	}
}

void setPortrait(const Point& blockPoint)
{
	//????????????????????????map???????????????????????????
	//
	//	??????	(?????????blockPoint?????????)
	//	??????
	//	??????
	//	??????
	for (int i = 0; i < 2; ++i)
	{
		for (int j = 0; j < 4; ++j)
		{
			map[blockPoint.x + i][blockPoint.y + j] = c;
		}
	}
}

bool dfs(Point point, int color) //color????????£????????????????????¨??????
{
	//??¢?´¢??????????????????????????¨??????????????°??????0??????????????????
	map[point.x][point.y] = 0;

	if (point == goal)
	{
		return true;
	}
	//???????????????????????????????????´????????´???????????????????????????????????????
	bool upCase = false;
	bool downCase = false;
	bool leftCase = false;
	bool rightCase = false;
	//?????¨?????°?????????????????????????????????????????°???
	Point upPoint = Point(point.x, point.y - 1);
	Point downPoint = Point(point.x, point.y + 1);
	Point leftPoint = Point(point.x - 1, point.y);
	Point rightPoint = Point(point.x + 1, point.y);

	//??????????????????????????????????????°???????????????????????????????????????????????????
	if (upPoint.y >= 1 && map[upPoint.x][upPoint.y] == color)
	{
		upCase = dfs(upPoint, color);
	}
	if (downPoint.y <= h && map[downPoint.x][downPoint.y] == color)
	{
		downCase = dfs(downPoint, color);
	}
	if (leftPoint.x >= 1 && map[leftPoint.x][leftPoint.y] == color)
	{
		leftCase = dfs(leftPoint, color);
	}
	if (rightPoint.x <= w && map[rightPoint.x][rightPoint.y] == color)
	{
		rightCase = dfs(rightPoint, color);
	}

	return (upCase || downCase || leftCase || rightCase);
}

int main()
{
	while (true)
	{
		//?????????????????????
		for (int i = 0; i < 105; ++i)
		{
			for (int j = 0; j < 105; ++j)
			{
				map[i][j] = 0;
			}
		}

		//??????????????§????????\???
		cin >> w >> h;
		if (w == 0 && h == 0) return 0;

		//??????????????°????????´????????°?????\???
		cin >> start.x >> start.y;
		cin >> goal.x >> goal.y;

		//????????????????????° n ?????\???
		cin >> n;

		//???????????????????????±??\???
		for (int i = 0; i < n; ++i)
		{
			cin >> c >> d >> blockPoint.x >> blockPoint.y;
			if (d == 0)
			{
				setSideways(blockPoint);
			}
			if (d == 1)
			{
				setPortrait(blockPoint);
			}
		}

		int startColor = map[start.x][start.y];
		if (startColor != 0 && dfs(start, startColor))
		{
			cout << "OK" << endl;
		}
		else
		{
			cout << "NG" << endl;
		}
	}
	return 0;
}

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

typedef std::pair<int, int> P;

int w, h;
int field[100][100];
int xs, ys, xg, yg;
int n;
const int dx[4] = { 0, 1, 0, -1 }, dy[4] = { -1, 0, 1, 0 };

int main()
{
	while( std::cin >> w >> h, w | h )
	{
		memset( field, 0, sizeof( field ) );

		std::cin >> xs >> ys >> xg >> yg >> n;
		for( int i = 0; i != n; ++i )
		{
			int c, d, x, y;
			std::cin >> c >> d >> x >> y;
			for( int j = 0; j != 8; ++j )
			{
				int nx = x + ( d ? j % 2 : j / 2 ),
					ny = y + ( d ? j / 2 : j % 2 );

				field[ny-1][nx-1] = c;
			}
		}

		std::queue<P> que;
		int col = field[ys-1][xs-1];
		bool ans = false;
		que.push( P( xs, ys ) );

		while( !que.empty() )
		{
			P p = que.front(); que.pop();
			if( p.first == xg && p.second == yg )
			{
				ans = true;
				break;
			}

			field[p.second-1][p.first-1] = 0;

			for( int i = 0; i != 4; ++i )
			{
				int nx = p.first + dx[i],
					ny = p.second + dy[i];
				
				if( nx > 0 && nx <= w && ny > 0 && ny <= h && field[ny-1][nx-1] && field[ny-1][nx-1] == col )
					que.push( P( nx, ny ) );
			}
		}

		std::cout << ( ans ? "OK" : "NG" ) << std::endl;
	}

	return 0;
}