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<stack>
#include<string.h>
using namespace std;
struct ST {
	int a;
	int b;
	int c;
};
long long brock[1000][1000];
long long ds[1000][1000];
int q[4]={0,-1,0,1};
int p[4]={1,0,-1,0};
int main(){
	stack <ST> S;
	ST ma;
	ST ba;
	int w,h;//???????????§??????
	int xs,ys;//??????????????§?¨?
	int xg,yg;//??´????????§?¨?
	int n;//????????????????????°
	int c,d,x,y;//????????????????????±
	int i,j,m,check=0;
	while(1){
		memset(ds,0,sizeof(ds));
		memset(brock,0,sizeof(brock));
		cin>>w>>h;//???????????§????????\???
		if(w==0&&h==0){
			break;
		}
		cin>>xs>>ys>>xg>>yg;//??????????????¨??´???????????§?¨???\???
		cin>>n;//????????????????????°
		for(i=0;i<n;i++){
			cin>>c>>d>>x>>y;
			if(d==1){//???
				for(m=0;m<2;m++){
					for(j=0;j<4;j++){
						brock[x+m][y+j]=c;
					}
				}
			}
			else{//?¨?
				for(m=0;m<4;m++){
					for(j=0;j<2;j++){
						brock[x+m][y+j]=c;
					}
				}
			}
		}
		if(brock[xs][ys]!=brock[xg][yg]){
			cout<<"NG"<<endl;
		}
		else{
			ma.a=xs;
			ma.b=ys;
			ma.c=brock[xs][ys];
			ds[xs][ys]=1;
			S.push(ma);
			check=0;
			while(!S.empty()){
				ba=S.top();
				S.pop();
				ds[ba.a][ba.b]=1;
				if(ba.a==xg&&ba.b==yg){
					check=1;
				}
				if(ba.c!=brock[xg][yg]){
					S.pop();
				}
				else{
					for(i=0;i<4;i++){
						if(ba.a+p[i]>0&&ba.a+p[i]<=w&&ba.b+q[i]>0&&ba.b+q[i]<=h&&ds[ba.a+p[i]][ba.b+q[i]]==0){
							ma.a=ba.a+p[i];
							ma.b=ba.b+q[i];
							ma.c=ba.c;
							S.push(ma);
						}
					}
				}
			}
			if(check==1){
				cout<<"OK"<<endl;
			}
			else{
				cout<<"NG"<<endl;
			}
		}
	}
	return 0;
}

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

int F[102][102];

bool DFS(int X, int Y, int Xg, int Yg, int c){
	if(F[Y][X] != c){
		return false;
	}else if(F[Y][X] == c && X == Xg && Y == Yg){
		return true;
	}
	F[Y][X] = -1;
	if(DFS(X, Y - 1, Xg, Yg, c)){
		return true;
	}else if(DFS(X + 1, Y, Xg, Yg, c)){
		return true;
	}else if(DFS(X, Y + 1, Xg, Yg, c)){
		return true;
	}else if(DFS(X - 1, Y, Xg, Yg, c)){
		return true;
	}
	
	return false;
}

int main(){
while(true){
	int w, h;
	cin >> w >> h;
	if(w == 0 && h == 0){
		break;
	}
	int xs, ys, xg, yg;
	cin >> xs >> ys >> xg >> yg;
	int n;
	cin >> n;
	for(int y = 0; y < 102; y++){
		for(int x = 0; x < 102; x++){
			F[y][x] = -1;
		}
	}
	for(int i = 0; i < n; i++){
		int c, d, x, y;
		cin >> c >> d >> x >> y;
		if(d == 0){
			for(int X = x; X < x + 4; X++){
				for(int Y = y; Y < y + 2; Y++){
					F[Y][X] = c;
				}
			}
		}else if(d == 1){
			for(int X = x; X < x + 2; X++){
				for(int Y = y; Y < y + 4; Y++){
					F[Y][X] = c;
				}
			}
		}
	}
	if(F[ys][xs] != -1){
		if(DFS(xs, ys, xg, yg, F[ys][xs])){
			cout << "OK" << endl;
		}else{
			cout << "NG" << endl;
		}
	}else{
			cout << "NG" << endl;
	}
}
	return 0;
}

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

class Solve{
private:
    int board[101][101] = {{0},{0},};
    int board_weight;
    int board_hight;
    int start_x;
    int start_y;
    int goal_x;
    int goal_y;
    int start_color;
    const int vector_x[4] = {0, 0, -1, 1};
    const int vector_y[4] = {1, -1, 0, 0};
    bool flag = false;
    void dfs(int x, int y);
public:
    Solve(int Board_Weight, int Board_Hight, int Start_X, int Start_Y, int Goal_X, int Goal_Y);
    void set_Block(int Color, int Direction, int X, int Y);
    bool check();
};

Solve::Solve(int Board_Weight, int Board_Hight, int Start_X, int Start_Y, int Goal_X, int Goal_Y){
    board_weight = Board_Weight;
    board_hight  = Board_Hight;
    start_x      = Start_X - 1;
    start_y      = Start_Y - 1;
    goal_x       = Goal_X - 1;
    goal_y       = Goal_Y - 1;
}
void Solve::set_Block(int Color, int Direction, int X, int Y){
    X -= 1; Y -= 1;
    if(X == start_x && Y == start_y){
        start_color = Color;
    }
    if(Direction == 0){
        for(int h = 0;h < 2;h++){
            for(int w = 0;w < 4;w++){
                board[Y+h][X+w] = Color;
            }
        }
    }else{
        for(int h = 0;h < 4;h++){
            for(int w = 0;w < 2;w++){
                board[Y+h][X+w] = Color;
            }
        }
    }
}
bool Solve::check(){
    Solve::dfs(start_x, start_y);
    return flag;
}

void Solve::dfs(int X, int Y){
    if(X == goal_x && Y == goal_y){
        flag = true;
        return;
    }
    
    for(int y = 0;y < 4;y++){
        for(int x = 0;x < 4;x++){
            int new_x = X + vector_x[x];
            int new_y = Y + vector_y[y];
            
            if(new_x >= 0 && new_x < board_weight){
                if(new_y >= 0 && new_y < board_hight){
                    if(start_color == board[new_y][new_x]){
                        board[Y][X] = 9;
                        dfs(new_x, new_y);
                    }
                }
            }
        }
    }
    return;
}

int main()
{
    int w, h, sx, sy, gx, gy, n, c, d, x, y;
    
    while(true){
        cin >> w >> h;
        if(w != 0 && h != 0){
            cin >> sx >> sy >> gx >> gy >> n;
            Solve s(w, h, sx, sy, gx, gy);
            
            for(int i = 0;i < n;i++){
                cin >> c >> d >> x >> y;
                s.set_Block(c, d, x, y);
            }
            
            if(s.check() == true){
                cout << "OK\n";
            }else{
                cout << "NG\n";
            }
        }else{
            break;
        }
    }
    
    return 0;
}