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_W(int Y,int X,int Xg,int Yg,int c){
  if(Y==Xg&&X==Yg){
    c=1;
  }
  if((F[Y][X]!='w')||(c!=0)){
    return;
  }
  F[Y][X]='.';
  DFS_W(Y-1,X  ,Xg,Yg,c);
  DFS_W(Y  ,X+1,Xg,Yg,c);
  DFS_W(Y+1,X  ,Xg,Yg,c);
  DFS_W(Y  ,X-1,Xg,Yg,c);
}
void DFS_Y(int Y,int X,int Xg,int Yg,int &c){
  if(Y==Xg&&X==Yg){
    c=1;
  }
  if((F[Y][X]!='y')||(c!=0)){
    return;
  }
  F[Y][X]='.';
  DFS_Y(Y-1,X  ,Xg,Yg,c);
  DFS_Y(Y  ,X+1,Xg,Yg,c);
  DFS_Y(Y+1,X  ,Xg,Yg,c);
  DFS_Y(Y  ,X-1,Xg,Yg,c);
}
void DFS_G(int Y,int X,int Xg,int Yg,int &c){
  if((Y==Xg&&X==Yg)||(c!= 0)){
    c=1;
  }
  if(F[Y][X]!='g'){
    return;
  }
  F[Y][X]='.';
  DFS_G(Y-1, X  ,Xg,Yg,c);
  DFS_G(Y  ,X+1,Xg,Yg,c);
  DFS_G(Y+1,X  ,Xg,Yg,c);
  DFS_G(Y  ,X-1,Xg,Yg,c);
}
void DFS_B(int Y,int X,int Xg,int Yg,int &c){
  if(Y==Xg&&X==Yg){
    c=1;
  }
  if((F[Y][X]!='b')||(c!=0)){
    return;
  }
  F[Y][X]='.';
  DFS_B(Y-1,X  ,Xg,Yg,c);
  DFS_B(Y  ,X+1,Xg,Yg,c);
  DFS_B(Y+1,X  ,Xg,Yg,c);
  DFS_B(Y  ,X-1,Xg,Yg,c);
}
void DFS_R(int Y,int X,int Xg,int Yg,int &c){
  if(Y==Xg&&X==Yg){
    c=1;
  }
  if((F[Y][X]!='r')||(c!=0)){
    return;
  }
  F[Y][X]='.';
  DFS_R(Y-1,X  ,Xg,Yg,c);
  DFS_R(Y  ,X+1,Xg,Yg,c);
  DFS_R(Y+1,X  ,Xg,Yg,c);
  DFS_R(Y  ,X-1,Xg,Yg,c);
}

int main(){

  for(int i=0;i<101;i++){
    for(int j=0;j<101;j++){
      F[j][i]='0';
    }
  }
  int w;
  int h;
  int xs;
  int ys;
  int xg;
  int yg;
  int n;
  cin>>w>>h;
  while(1){
    //int a=0;
    //int b=0;
    cin>>xs>>ys;
    cin>>xg>>yg;
    cin>>n;
    int c[n];
    int d[n];
    int x[n];
    int y[n];
    for(int i=0;i<n;i++){
      cin>>c[i]>>d[i]>>x[i]>>y[i];
      //int a=0;
      //int b=0;
      if(d[i]==0) {
        if(c[i]==1){
          for(int z=0;z<4;z++){
            F[y[i]][x[i]+z] ='w';
            F[y[i]+1][x[i]+z] ='w';
          }
        }else if(c[i]==2){

          for(int z=0;z<4;z++){
            F[y[i]][x[i]+z] ='y';
            F[y[i]+1][x[i]+z] ='y';
          }
        }else if(c[i]==3){
          for(int z=0;z<4;z++){
            F[y[i]][x[i]+z] ='g';
            F[y[i]+1][x[i]+z] ='g';
          }
        }else if(c[i]==4){
          for(int z=0;z<4;z++){
            F[y[i]][x[i]+z] ='b';
            F[y[i]+1][x[i]+z] ='b';
          }
        }else if(c[i]==5){
          for(int z=0;z<4;z++){
            F[y[i]][x[i]+z] ='r';
            F[y[i]+1][x[i]+z] ='r';
          }
        }
      }else if(d[i]==1){
        if(c[i]==1){
          for(int z=0;z<4;z++){
            F[y[i]+z][x[i]] ='w';
            F[y[i]+z][x[i]+1] ='w';
          }
        }else if(c[i]==2){
          for(int z=0;z<4;z++){
            F[y[i]+z][x[i]] ='y';
            F[y[i]+z][x[i]+1] ='y';
          }
        }else if(c[i]==3){
          for(int z=0;z<4;z++){
            F[y[i]+z][x[i]] ='g';
            F[y[i]+z][x[i]+1] ='g';
          }
        }else if(c[i]==4){
          for(int z=0;z<4;z++){
            F[y[i]+z][x[i]] ='b';
            F[y[i]+z][x[i]+1] ='b';
          }
        }else if(c[i]==5){
          for(int z=0;z<4;z++){
            F[y[i]+z][x[i]] ='r';
            F[y[i]+z][x[i]+1] ='r';
          }
        }
      }
    }
    int cnt=0;
    if(F[ys][xs]=='w'){
      DFS_W(ys,xs,xg,yg,cnt);
    }else if(F[ys][xs]=='y'){
      DFS_Y(ys,xs,xg,yg,cnt);
    }else if(F[ys][xs]=='g'){
      DFS_G(ys,xs,xg,yg,cnt);
    }else if(F[ys][xs]=='b'){
      DFS_B(ys,xs,xg,yg,cnt);
    }else if(F[ys][xs]=='r'){
      DFS_R(ys,xs,xg,yg,cnt);
    }
    if(cnt==0){
      cout<<"NG"<<endl;
    }else if(cnt==1){
      cout<<"OK"<<endl;
    }
    cin>>w>>h;
    if((w==0)&&(h==0))
      break;
    for(int i=0;i<101;i++){
      for(int j=0;j<101;j++){
        F[i][j]='0';
      }
    }
  }
  return 0;
}

C++: #include<iostream>
using namespace std;
#define MAX_H 100
#define MAX_W 100
#define INF 1000;
int h,w;
int field[MAX_H][MAX_W];
int dx[4]={0,-1,0,1},dy[4]={-1,0,1,0};
void dfs(int y,int x,const int sc){
	if(y<=0 || x<=0 || y>h || x>w)return;
	if(field[y][x]==sc){
		field[y][x]=0;
		for(int i=0;i<4;i++)dfs(y+dy[i],x+dx[i],sc);
	}
	return;
}
int main(){
	int sx,sy,gx,gy,n;
	while(cin>>w>>h){
        if(!w && !h)break;
		cin>>sx>>sy>>gx>>gy>>n;
		for(int i=0;i<MAX_H;i++){
			for(int j=0;j<MAX_W;j++){
					field[i][j]=INF;
				}
		}
		while(n--){
			int c,d,x,y;
			cin>>c>>d>>x>>y;
			for(int i=0;i<2;i++){
				for(int j=0;j<4;j++){
					if(d)field[y+j][x+i]=c;
					else field[y+i][x+j]=c;
				}
			}
		}
		dfs(sy,sx,field[sy][sx]);
		if(field[gy][gx])cout<<"NG"<<endl;
		else cout<<"OK"<<endl;

	}
	return 0;
}