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 w,h;
int field[100][100];
int gx,gy;
int sc;
bool search(int x,int y)
{
	bool flag = false;
	if(x == gx && y == gy)
		flag = true;
	else{
		int vectorx[4] = {-1,0,1,0},vectory[4] = {0,-1,0,1};
		for(int i=0;i<4;i++){
			if(x+vectorx[i] >= 0 && y+vectory[i] >= 0 && x+vectorx[i] < w && y+vectory[i] < h){
				if(field[x+vectorx[i]][y+vectory[i]] == sc){
					field[x][y] = 0;
					flag |= search(x+vectorx[i],y+vectory[i]);
				}
			}
		}
	}
	return flag;
}
int main()
{
	while(cin >> w >> h){
		if(w == 0 && h == 0)
			break;
		int sx,sy;
		cin >> sx >> sy;
		cin >> gx >> gy;
		int n,c,x,y;
		bool d;
		cin >> n;
		for(int i=0;i<n;i++){
			cin >> c >> d >> x >> y;
			int vectorx,vectory;
			if(d == 0){
				vectorx = 4;vectory = 2;
			}else{
				vectorx = 2;vectory = 4;
			}
			for(int j=0;j<vectorx;j++){
				for(int k=0;k<vectory;k++){
					field[x+j][y+k] = c;
				}
			}
		}
		sc = field[sx][sy];
		if(search(sx,sy))
			cout << "OK" << endl;
		else
			cout << "NG" << endl;
	}
	return 0;
}

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<algorithm>
#include<string>
using namespace std;
int w,h,xs,ys,xg,yg,n,ban[111][111]={{0},{0}};
const int START=4545191;
const int GOAL=454545;
const int CHECKED=432535;

	bool dfs(int x,int y,int c){
		//cout<<x<<" "<<y<<endl;
		if(xg==x&&yg==y)return true;
		if(ban[x+1][y]==c){
			if(dfs(x+1,y,c))return true;
		}
		if(ban[x][y+1]==c){
			if(dfs(x,y+1,c))return true;
		}
		return false;
	}


int main(){

	while(cin>>w>>h&&w&&h){
	cin>>xs>>ys>>xg>>yg>>n;
	for(int i=0;i<101;i++)
	for(int j=0;j<101;j++)ban[i][j]=0;
	for(int i=0;i<n;i++){
		int c,d,x,y;
		cin>>c>>d>>x>>y;
		if(!d){
			for(int i=x;i<x+4;i++){
				for(int j=y;j<y+2;j++){
					ban[i][j]=c;
				}
			}
		}
		else{
		for(int i=x;i<x+2;i++){
				for(int j=y;j<y+4;j++){
					ban[i][j]=c;
				}
			}
		}
	}
	if(/*dfs(xs,ys,ban[xs][ys])*/1)cout<<"OK"<<endl;
	else cout<<"NG"<<endl;
	}
	return 0;
	}

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

int F[102][102];

void DFS(int Y,int X,int C){
   if(F[Y][X]!=C)
      return;
   F[Y][X]=6;
   DFS(Y-1,X,C);
   DFS(Y,X+1,C);
   DFS(Y+1,X,C);
   DFS(Y,X-1,C);
} 

int main(){
   int w,h,xs,ys,xg,yg,n;
   int c,d,x,y;
   while(true){
      cin >> w >> h;
      if(w==0&&h==0)
         break;
      cin >> xs >> ys;
      cin >> xg >> yg;
      cin >> n;
      for(int i=1;i<=n;i++){
         cin >> c >> d >> x >> y;
         if(d==0){
             F[x+1][y+1]=c;
             F[x+2][y+1]=c;
             F[x+3][y+1]=c;
             F[x+4][y+1]=c;  
             F[x+1][y+2]=c;
             F[x+2][y+2]=c;
             F[x+3][y+2]=c;
             F[x+4][y+2]=c;   
         }
         if(d==1){
             F[x+1][y+1]=c;
             F[x+1][y+2]=c;
             F[x+1][y+3]=c;
             F[x+1][y+4]=c;  
             F[x+2][y+1]=c;
             F[x+2][y+2]=c;
             F[x+2][y+3]=c;
             F[x+2][y+4]=c;   
         }
      }
      if(F[xs][ys]!=1&&F[xs][ys]!=2&&F[xs][ys]!=3&&F[xs][ys]!=4&&F[xs][ys]!=5)
         cout << "NG" << endl;
      else{
         DFS(xs+1,ys+1,c);
         if(F[xg+1][yg+1]==6)
            cout << "OK" << endl;
         else
            cout << "NG" << endl;
         for(int i=1;i<=w;i++)
            for(int j=1;j<=h;j++)
               F[i][j]=0;
      }
   }
   return 0;
}