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 Board[102][102];    //Board[j, x, w][i, y, h]
bool isOK;              //迷路がOKかNGか
int xs, ys, xg, yg;     //StartとGoalの座標

void DFS(int c, int x, int y){
    if(Board[x][y] != c){
        return;
    }
    else if(x==xg && y==yg){
        isOK = true;    //Goalなら迷路はOK
        return;
    }

    Board[x][y] = 0;

    DFS(c, x+1, y  );
    DFS(c, x  , y+1);
    DFS(c, x-1, y  );
    DFS(c, x  , y-1);
}

int main(){
    int w,h;
    while(true){
        cin >> w >> h;
        if(w==0 && h==0)
            break;
        
        isOK = false;               //初期値をNGに
        for(int i=0;i<102;i++){     //Boardの初期化
            for(int j=0;j<102;j++)
                Board[j][i] = -1;
        }
        cin >> xs >> ys >> xg >> yg;

        int n, c, d, x, y;
        cin >> n;
        for(int t=0;t<n;t++){
            cin >> c >> d >> x >> y;
            int wb = 2+(!d*2);      //d=0なら横長
            int hb = 2+(d*2);       //d=1なら縦長
            for(int i=0;i<hb;i++){
                for(int j=0;j<wb;j++)
                    Board[x+j][y+i] = c;
            }
        }

        DFS(Board[xs][ys], xs, ys);

        if(isOK)
            cout << "OK" << endl;
        else
            cout << "NG" << endl;

    }

    return 0;
}

C++: #include <iostream>
#include <queue>
#include <cstring>
const int MAX_W = 100, MAX_H = 100;

typedef std::pair<int,int> P;
int map[MAX_H + 1][MAX_W + 1];

int bfs(P sp, P gp, int w, int h){
	//½±Æª é©ði[
	int f[MAX_H + 1][MAX_W + 1] = {{0}};
	std::queue<P> q;
	q.push(P(sp.first, sp.second));
	
	while(q.size()){
		P p = q.front(); q.pop();
		//S[Å«½ç¬÷
		if(p.first == gp.first && p.second == gp.second)return 1;
		
		int vy[4] = {-1,1,0,0}, vx[4] = {0,0,-1,1};
		for(int i=0;i<4;i++){
			int nx = p.first + vx[i],
				ny = p.second + vy[i];
			if(nx >= 0 && nx <= w && ny >= 0 && ny <= h && 
				 map[ny][nx] > 0 && !f[ny][nx]){
				q.push(P(nx,ny));
				f[ny][nx] = 1;
			}
		}
	}

	//ÅãÜÅS[Å«È¢Èç¸s
	return 0;
}

int main(){
	int w, h, xs, ys, xg, yg;
	while(std::cin >> w >> h, w){
		memset(map,0,sizeof(map));
		std::cin >> xs >> ys;
		std::cin >> xg >> yg;

		int n;
		std::cin >> n;

		//ubNÌÝu
		while(n--){
			int c, d, x, y;
			std::cin >> c >> d >> x >> y;
			
			int mx, my;
			if(d)//w < h
				{my = 4, mx = 2;}
			else//w > h
				{mx = 4, my = 2;}
			for(int i=y;i<y+my;i++){
				for(int j=x;j<x+mx;j++){
					map[i][j] = 1;
				}
			}
		}

		//bfsÅS[Å«é©mF
		P sp = P(xs,ys), gp = P(xg,yg);
		if(bfs(sp, gp, w, h))std::cout << "OK" << std::endl;
		else{std::cout << "NG" << std::endl;}
	}
}

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

int weight, hight;
int g[101][101];
int sc;
int sx, sy, gx, gy;
bool flag = false;
const int vx[4] = {0, 0, -1, 1};
const int vy[4] = {1, -1, 0, 0};

void dfs(int x, int y){
    if(x == gx && y == gy){
        flag = true;
        return;
    }

    for(int i = 0;i < 4;i++){
        int nx = x + vx[i];
        int ny = y + vy[i];
        
        if(nx >= 0 && nx < weight && ny >= 0 && ny < hight && g[ny][nx] == sc){
            g[y][x] = 8;
            dfs(nx, ny);
        }
    }
}

int main(){ 
    while(cin >> weight >> hight){
        if(weight == 0 && hight == 0){
            break;
        }
        
        int dn, c, d, x, y;
        flag = false;
        g[101][101] = {};
        
        cin >> sx >> sy >> gx >> gy >> dn;
        
        for(int i = 0;i < dn;i++){
            cin >> c >> d >> x >> y;
            
            if(d == 0){
                for(int h = 0;h < 2;h++){
                    for(int w = 0;w < 4;w++){
                        g[y+h][x+w] = c;
                    }
                }
            }else{
                for(int h = 0;h < 4;h++){
                    for(int w = 0;w < 2;w++){
                        g[y+h][x+w] = c;
                    }
                }
            }
        }
        
        sc = g[sy][sx];
        dfs(sx, sy);
        
        if(flag){
            cout << "OK" << endl;
        }else{
            cout << "NG" << endl;
        }
    }
    
    return 0;
}

C++: #include<iostream>
#include<cstdio>
using namespace std;
int w,h,xs,ys,xg,yg,n;
int c,d,x,y,ans,f=0;
int map[100][100],v[100][100]={0};
int root(int x,int y,int vmap[][100]){
	int mx[]={0,1,0,-1},fx;
	int my[]={1,0,-1,0},fy;
	if(x==xg&&y==yg){
		f=1;
		return f;
	}
	for(int i=0;i<4;i++){
		fx=x+mx[i];
		fy=y+my[i];
		if(map[fy][fx]==map[xs][ys]&&fy>=0&&fy<h&&fx>=0&&fx<w&&vmap[fy][fx]==0){
			vmap[fy][fx]=1;
			return root(fx,fy,vmap);
		}
	}
	return 0;
}
int main(){
	scanf("%d %d",&w ,&h);
	while(w!=0&&h!=0){
		scanf("%d %d %d %d %d",&xs ,&ys ,&xg ,&yg ,&n);
		for(int i=0;i<n;i++){
			scanf("%d %d %d %d",&c ,&d ,&x ,&y);
			if(d==0){
				for(int w=x;w<x+4;w++){
					for(int h=y;h<y+2;h++){
						map[h][w]=c;
					}
				}
			}
			if(d==1){
				for(int w=x;w<x+2;w++){
					for(int h=y;h<y+4;h++){
						map[h][w]=c;
					}
				}
			}
		}
		x=xs;
		y=ys;
		ans=root(x,y,v);
		if(ans==1){
			printf("OK\n");
		}
		else{
			printf("NG\n");
		}
		scanf("%d %d",&w ,&h);
	}
	return 0;
}