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];

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

int main(){
  int c[5];
  int d[1];
  int w;
  int h;
  int xs;
  int ys;
  int xg;
  int yg;
  int n;
  int x[n];
  int y[n];
  cin>>w>>h;
  while(w!=0){
    int a=0;
    int b=0;
    cin>>xs>>ys;
    cin>>xg>>yg;
    cin>>n;
    for(int i=1;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'){
      cnt=DFS_W(ys,xs,xg,yg,cnt);
    }else if(F[ys][xs]=='y'){
      cnt=DFS_Y(ys,xs,xg,yg,cnt);
    }else if(F[ys][xs]=='g'){
      cnt=DFS_G(ys,xs,xg,yg,cnt);
    }else if(F[ys][xs]=='b'){
      cnt=DFS_B(ys,xs,xg,yg,cnt);
    }else if(F[ys][xs]=='r'){
      cnt=DFS_R(ys,xs,xg,yg,cnt);
    }
    if(cnt==0){
      cout<<"NG"<<endl;
    }else if(cnt==1){
      cout<<"OK"<<endl;
    }
    cin>>w>>h;
  }
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;

bool b;
int dx[]={1,0,-1,0};
int dy[]={0,1,0,-1};

void dfs(int a[][101] ,int x , int y , int w , int h , int xg , int yg , int sc){
	if(x==xg&&y==yg) {b=true;return;}
	for(int i=0;i<4;++i){
		int tx=x+dx[i];
		int ty=y+dy[i];
		if(tx<=0||ty<=0||tx>w||ty>h) continue;
		if(a[tx][ty]!=sc || a[tx][ty]==0) continue;
		if(b) continue;
		dfs( a,tx,ty,w,h,xg,yg,sc);
	}
}

int main(){
	int w , h;
	while(cin >> w >> h , w||h){
		int xs , ys , xg , yg ;
		int n;
		b=false;
		int board[101][101]={0};
		cin >> xs >> ys >> xg >> yg >> n;
		for(int i=0;i<n;++i){
			int c , d , x , y;
			cin >> c >> d >> x >> y;
			if(!d){
				for(int k=0;k<2;++k){
					for(int j=0;j<4;++j){
						board[x+j][y+k]=c;
					}
				}
			} else {
				for(int k=0;k<4;++k){
					for(int j=0;j<2;++j){
						board[x+j][y+k]=c;
					}
				}
			}
		}
		int sc=board[xs][ys];
		int gc=board[xg][yg];
		if(sc!=gc) {}
		else dfs(board ,xs,ys , w , h , xg , yg , sc);
		cout << ( b ? "OK" : "NG") << endl;
	}
	return 0;
}

C++: #include <iostream>
using namespace std;
  
int F[105][105];
int xg,yg,w,h;
  
  
void DFS(int Y,int X,int c){
  if(F[Y][X] != c){
    return;
  }
  
  F[Y][X] = -1;
  DFS(Y+1,X  ,c);
  DFS(Y-1  ,X,c);
  DFS(Y,X+1  ,c);
  DFS(Y  ,X-1,c);
}
  
  
int main(){
  int xs,ys,n;
  while(1){
    cin >> w >> h;
    if(w == 0 && h == 0)
      break;
for(int i=0; i<105; i++){
      for(int j=0; j<105; j++){
        F[i][j]=10;
      }
    }
      
    cin >> xs >> ys >> xg >> yg >> n;
  
  
    for(int i=0;i<n;i++){
      int c,d,x,y;
      cin >> c >> d >> x >> y;
      //if(c == 0)
        //c = 2345;
      if(d == 0){
        for(int j=0;j<4;j++){
          F[x+j][y] = c;
          F[x+j][y+1] = c;
        }
      } else {
        for(int j=0;j<4;j++){
          F[x][y+j] = c;
          F[x+1][y+j] = c;
        }
      }
    }
 
  DFS(xs,ys,F[xs][ys]);
  
  if(F[xg][yg] == -1){
    cout << "OK" << endl;
  } else {
    cout << "NG" <<endl;
  }
  }
}