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==0){
				for(m=y;m<y+2;m++){
					for(j=x;j<x+4;j++){
						brock[m][j]=c;
					}
				}
			}
			else{
				for(m=y;m<y+4;m++){
					for(j=x;j<x+2;j++){
						brock[m][j]=c;
					}
				}
			}
		}
		/*for(i=1;i<h;i++){
			for(j=1;j<w;j++){
				cout<<brock[i][j];
			}
			cout<<endl;
		}*/
		if(brock[ys][xs]!=brock[yg][xg]){
			cout<<"NG"<<endl;
		}
		else{
			ma.a=ys;
			ma.b=xs;
			ma.c=brock[ys][xs];
			ds[ys][xs]=1;
			S.push(ma);
			check=0;
			while(!S.empty()){
				ba=S.top();
				S.pop();
				ds[ba.a][ba.b]=1;
				if(ba.a==yg&&ba.b==xg){
					check=1;
					break;
				}
				if(ba.c==brock[yg][xg]){
					for(i=0;i<4;i++){
						if(ba.a+p[i]>0&&ba.a+p[i]<=h&&ba.b+q[i]>0&&ba.b+q[i]<=w&&ds[ba.a+p[i]][ba.b+q[i]]==0){
							ma.a=ba.a+p[i];
							ma.b=ba.b+q[i];
							ma.c=brock[ba.a+p[i]][ba.b+q[i]];
							S.push(ma);
						}
					}
				}
			}
			if(check==1){
				cout<<"OK"<<endl;
			}
			else{
				cout<<"NG"<<endl;
			}
		}
	}
	return 0;
}

C++: #include<iostream>
#include<stack>
#include<vector>
using namespace std;
class point {
public:
	int color;
	bool used;
	point():color(-1),used(false){}
};
int main() {
	int X, Y;
	int make[][2] = { {2,4},{4,2} };
	while (cin >> X >> Y&&X != 0) {
		vector<vector<point> > map(X + 2, vector<point>(Y + 2));
		int sx, sy, gx, gy;
		cin >> sx >> sy >> gx >> gy;
		int n;
		cin >> n;
		for (int i = 0; i < n; ++i) {
			int color, d, x, y;
			cin >> color >> d >> x >> y;
			for (int dx = 0; dx < make[d][1]; ++dx) {
				for (int dy = 0; dy < make[d][0]; ++dy) {
					map[x + dx][y + dy].color = color;
				}
			}
		}
		stack<pair<int, int> > st;
		if (map[sx][sy].color != -1) {
			st.push(pair<int, int>(sx, sy));
		}
		int mx[] = { 1,0,-1,0 }, my[] = { 0,1,0,-1 };
		while (!st.empty()) {
			pair<int,int> dummy = st.top(); st.pop();
			if (map[dummy.first][dummy.second].used)continue;
			map[dummy.first][dummy.second].used = true;
			for (int i = 0; i < 4; ++i) {
				int x = dummy.first + mx[i];
				int y = dummy.second + my[i];
				if (map[dummy.first][dummy.second].color == map[x][y].color&&map[x][y].used == false) {
					st.push(pair<int, int>(x, y));
				}
			}
		}
		cout << (map[gx][gy].used ? "OK" : "NG") << endl;
	}
	return 0;
}

C++: #include <iostream>
#include<queue>
#include<string.h>
using namespace std;
#define TATE 1
#define YOKO 0
int main(void){
    int map[101][101];
    int board[101][101];
    int T[]={0,-1,1,0};
    int Y[]={1,0,0,-1};
    int w,h,xs,xg,ys,yg,n,color,muki,x,y;
    struct ST {
        int x;
        int y;
    };
    ST RE;
    ST GO;
    queue<ST> Q;
    while(1){
        memset(map,0,sizeof(map));
        memset(board,0,sizeof(board));
        cin>>w>>h;
        if(w==0&&h==0)break;
        cin>>xs>>ys>>xg>>yg>>n;
        for(int i=0;i<n;i++){
            cin>>color>>muki>>x>>y;
            if(muki==YOKO){
                for(int j=0;j<4;j++){
                    board[y][x+j]=board[y+1][x+j]=color;
                }
            }
            else{
                for(int j=0;j<4;j++){
                    board[y+j][x]=board[y+j][x+1]=color;
                }
            }
        }
       /* for(int i=1;i<=h;i++){
            for(int j=1;j<=w;j++){
                cout<<board[i][j];
            }
            cout<<endl;
        }*/
        RE.x=xs;
        RE.y=ys;
        map[ys][xs]=1;
        Q.push(RE);
        int flag=0;
        while(!Q.empty()){
            RE=Q.front();
            Q.pop();
            if(RE.x==xg&&RE.y==yg&&board[RE.y][RE.x]==board[yg][xg]){
                flag=1;
                //cout<<RE.x<<" "<<RE.y<<endl;
                break;
            }
            else{
                for(int i=0;i<4;i++){
                    GO=RE;
                    if(GO.x+Y[i]>0&&GO.y+T[i]>0&&GO.x+Y[i]<101&&GO.y+T[i]<101&&board[GO.y+T[i]][GO.x+Y[i]]==board[yg][xg]&&map[GO.y+T[i]][GO.x+Y[i]]!=1){
                        GO.x+=Y[i];
                        GO.y+=T[i];
                        map[GO.y][GO.x]=1;
                        Q.push(GO);
                    }
                }
            }
        }
       /* for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                cout<<board[i][j];
            }
            cout<<endl;
        }*/
        if(flag==1){
            cout<<"OK"<<endl;
        }
        else{
            cout<<"NG"<<endl;
        }
    }
    
}