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<algorithm>
using namespace std;
int field[101][101],b[101][101],X,Y,n,dx[4]={0,1,0,-1},dy[4]={1,0,-1,0},I,sX,sY,gX,gY,ans,sgc;
int func(int x,int y){
	for(I=0;I<4;I++){
		int xx=x+dx[I];
		int yy=y+dy[I];
		if(xx>0&&yy>0&&xx<=X&&yy<=Y&&field[xx][yy]==sgc&&b[xx][yy]==0){
			if(xx==gX&&yy==gY){
				if(ans==-1)ans=b[x][y];
				return 0;
			}
			else{
			b[xx][yy]=b[x][y]+1;
			func(xx,yy);
			}
		}
	}
	return 0;
}
int main(){
	int i,i2,c,d,x,y;
	cin>>X>>Y;
	while(X!=0){
		cin>>sX>>sY>>gX>>gY>>n;
		ans=-1;
		for(i=1;i<=100;i++){
			c=0;
			d=0;
			x=0;
			y=0;
			for(i2=1;i2<=100;i2++){
				field[i][i2]=0;
				b[i][i2]=0;
			}
		}
		for(i=1;i<=n;i++){
			cin>>c>>d>>x>>y;
			if(d==0){
				field[x][y]=c;
				field[x+1][y]=c;
				field[x+2][y]=c;
				field[x+3][y]=c;
				field[x][y+1]=c;
				field[x+1][y+1]=c;
				field[x+2][y+1]=c;
				field[x+3][y+1]=c;
			}
			else{
				field[x][y]=c;
				field[x][y+1]=c;
				field[x][y+2]=c;
				field[x][y+3]=c;
				field[x+1][y]=c;
				field[x+1][y+1]=c;
				field[x+1][y+2]=c;
				field[x+1][y+3]=c;
			}
		}
		for(i=1;i<=Y;i++){
			for(i2=1;i2<=X;i2++)cout<<field[i2][i]<<' ';
			cout<<endl;
		}
		sgc=field[sX][sY];
		func(sX,sY);
		for(i=1;i<=Y;i++){
			for(i2=1;i2<=X;i2++){
				if(b[i2][i]<10)cout<<' '<<b[i2][i]<<' ';
				else cout<<b[i2][i]<<' ';
			}
			cout<<endl;
		}
		if(ans==-1)cout<<"NG"<<endl;
		else cout<<"OK"<<endl;
		cin>>X>>Y;
	}
}

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

int f[102][102];

void draw(int c,int d,int x,int y){
    if(d){
        for(int i=x;i<x+2;i++){
            for(int j=y;j<y+4;y++){
                f[i][j]=c;
            }
        }
    }
}



bool DFS(int xs,int ys,int xg,int yg){
    while(xs!=xg||ys!=yg){
        if(DFS(xs+1,ys,xg,yg))
          xs++;
        else if(DFS(xs-1,ys,xg,yg))
          xs--;
        else if(DFS(xs,ys+1,xg,yg))
          ys++;
        else if(DFS(xs,ys-1,xg,yg))
          ys--;
        else{
            return false;
        }
    }
    return true;
}

int main(){
    int w,h;
    int xs,ys;
    int xg,yg;
    int n;
    int c;
    int d,x,y;
    while(1){
        cin>>w>>h;
        cin>>xs>>ys;
        cin>>xg>>yg;
        cin>>n;

        for(int i=0;i<n;i++){
            cin>>c>>d>>x>>y;
            draw(c,d,x,y);
        }
        if(DFS(xs,ys,xg,yg)){
            cout<<"OK"<<endl;
        }else{
            cout<<"NG"<<endl;
        }
    }
    return 0;
}

C++: #include<iostream>
#include<queue>
#define dr direction
#define cl color
#define fi first
#define se second

using namespace std;
typedef pair<int, int> pii;

class Block{
public:
    int color;// 1~5
    int direction;// 0:-, 1:|
    int x, y;
    void init(int c, int d, int xx, int yy);
};

void Block::init(int c, int d, int xx, int yy){
    color=c;
    direction=d;
    x=xx;
    y=yy;
}

int w, h, xs, ys, xg, yg, n;
int fld[100][100], dis[100][100];
const pii dxdy[]={{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
const int inf=1e8;

string solve(){// bfs
    queue<pii> qu;
    qu.push(make_pair(ys, xs));
    int C=fld[ys][xs];
    fill(dis[0], dis[100], inf);
    dis[ys][xs]=0;

    if(C==0) return "NO";
    while(!qu.empty()){
        pii now=qu.front(); qu.pop();
        if(now.fi==yg&&now.se==xg){
            return "OK";
        }

        for(int k=0; k<4; k++){
            pii nx=make_pair(now.fi+dxdy[k].fi, now.se+dxdy[k].se);
            if(!(0<=nx.fi&&nx.fi<h&&0<=nx.se&&nx.se<w)) continue;
            if(fld[nx.fi][nx.se]!=C) continue;
            if(dis[nx.fi][nx.se]!=inf) continue;

            dis[nx.fi][nx.se]=dis[now.fi][now.se]+1;
            qu.push(nx);
        }
    }

    return "NO";
}

int main(){

    while(1){
        cin>> w>> h;
        if(w==0&&h==0) break;
        cin>> xs>> ys>> xg>> yg>> n;
        xs--; ys--; xg--; yg--;
        Block block[n];
        for(int i=0; i<n; i++){
            int c, d, xx, yy;
            cin>> c>> d>> xx>> yy;
            xx--; yy--;
            block[i].init(c, d, xx, yy);
        }

        // make field
        for(int k=0; k<n; k++){
            int X=block[k].x, Y=block[k].y;
            if(block[k].dr==0){
                for(int i=0; i<2; i++){
                    for(int j=0; j<4; j++){
                        fld[Y+i][X+j]=block[k].cl;
                    }
                }
            }else{
                for(int i=0; i<4; i++){
                    for(int j=0; j<2; j++){
                        fld[Y+i][X+j]=block[k].cl;
                    }
                }
            }
        }
//*
        for(int i=0; i<w; i++){
            for(int j=0; j<h; j++){
                cout<< fld[i][j]<<" ";
            }
            cout<< endl;
        }
//*/
        cout<< solve()<< endl;
    }

    return 0;
}

C++: #include <cstdio>
#include <cstring>
#include <queue>
using namespace std;

bool block[6][110][110];
bool visit[110][110];

int main(){
	int w, h;
	int xs, ys, xg, yg;
	int n, c, d, x, y;
	while(scanf("%d%d%d%d%d%d%d", &w, &h, &xs, &ys, &xg, &yg, &n) == 7){
		memset(block, 0, sizeof block);
		memset(visit, 0, sizeof visit);

		for(int i = 0; i < n; ++i){
			scanf("%d%d%d%d", &c, &d, &x, &y);
			
			int dx, dy;
			if(d){ dx = 2; dy = 4; }
			else{  dy = 2; dx = 4; }

			for(int j = 0; j < dy; ++j)
			for(int k = 0; k < dx; ++k){
				block[c][y + j][x + k] = true;
			}
		}

		for(c = 5; c > 1 && !block[c][ys][xs]; --c);

		if(c){
			queue<int> q;
			q.push(ys << 16 | xs);
			visit[ys][xs] = true;
			while(!q.empty()){
				y = q.front() >> 16;
				x = q.front() & 0xffff;
				q.pop();

				for(int dy = -1; dy <= 1; ++dy)
				for(int dx = -1; dx <= 1; ++dx){
					if(block[c][y+dy][x+dx] && !visit[y+dy][x+dx]){
						visit[y+dy][x+dx] = true;
						q.push(y+dy << 16 | x+dx);
					}
				}
			}
		}

		puts(visit[yg][xg] ? "OK" : "NG");
	}
}