Go: package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func main() {
	io := NewIo()
	defer io.Flush()
	for {
		w, h := io.NextInt(), io.NextInt()
		if w == 0 {
			break
		}
		xWall := make([][]int, h)
		yWall := make([][]int, h)
		for i := 0; i < h; i++ {
			xWall[i], yWall[i] = make([]int, w), make([]int, w)
			for j := 0; j < w; j++ {
				xWall[i][j], yWall[i][j] = -1, -1
			}
		}
		for i := 0; i < h*2-1; i++ {
			if i%2 == 0 {
				for j := 0; j < w-1; j++ {
					xWall[i/2][j] = io.NextInt()
				}
			} else {
				for j := 0; j < w; j++ {
					yWall[i/2][j] = io.NextInt()
				}
			}
		}
		//io.Println(bfs(w, h, xWall, yWall))
		fmt.Println(bfs(w, h, xWall, yWall))
	}
}

type P struct {
	x, y int
}

func bfs(w, h int, x, y [][]int) int {
	d := make([][]int, h)
	for i := 0; i < h; i++ {
		d[i] = make([]int, w)
	}
	q := list.New()
	q.PushBack(P{0, 0})
	d[0][0] = 1

	for q.Len() != 0 {
		pos := q.Remove(q.Front()).(P)
		if pos.x == w-1 && pos.y == h-1 {
			break
		}
		if pos.x > 0 && x[pos.y][pos.x-1] == 0 && d[pos.y][pos.x-1] == 0 {
			d[pos.y][pos.x-1] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x - 1, pos.y})
		}
		if pos.x < w-1 && x[pos.y][pos.x] == 0 && d[pos.y][pos.x+1] == 0 {
			d[pos.y][pos.x+1] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x + 1, pos.y})
		}
		if pos.y > 0 && y[pos.y-1][pos.x] == 0 && d[pos.y-1][pos.x] == 0 {
			d[pos.y-1][pos.x] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x, pos.y - 1})
		}
		if pos.y < h-1 && y[pos.y][pos.x] == 0 && d[pos.y+1][pos.x] == 0 {
			d[pos.y+1][pos.x] = d[pos.y][pos.x] + 1
			q.PushBack(P{pos.x, pos.y + 1})
		}
	}
	return d[h-1][w-1]
}

// I/O template
type Io struct {
	reader    *bufio.Reader
	writer    *bufio.Writer
	tokens    []string
	nextToken int
}

func NewIo() *Io {
	return &Io{
		reader: bufio.NewReader(os.Stdin),
		writer: bufio.NewWriter(os.Stdout),
	}
}

func (io *Io) Flush() {
	err := io.writer.Flush()
	if err != nil {
		panic(err)
	}
}

func (io *Io) NextLine() string {
	var buff []byte
	for {
		line, isPrefix, err := io.reader.ReadLine()
		if err != nil {
			panic(err)
		}
		buff = append(buff, line...)
		if !isPrefix {
			break
		}
	}
	return string(buff)
}

func (io *Io) Next() string {
	for io.nextToken >= len(io.tokens) {
		line := io.NextLine()
		io.tokens = strings.Fields(line)
		io.nextToken = 0
	}
	s := io.tokens[io.nextToken]
	io.nextToken++
	return s
}

func (io *Io) NextInt() int {
	i, err := strconv.Atoi(io.Next())
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) NextFloat() float64 {
	i, err := strconv.ParseFloat(io.Next(), 64)
	if err != nil {
		panic(err)
	}
	return i
}

func (io *Io) Println(a ...interface{}) {
	fmt.Fprintln(io.writer, a...)
}

func (io *Io) Printf(format string, a ...interface{}) {
	fmt.Fprintf(io.writer, format, a...)
}

func (io *Io) PrintIntSlice(a []int) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func (io *Io) PrintStringSlice(a []string) {
	b := []interface{}{}
	for _, x := range a {
		b = append(b, x)
	}
	io.Println(b...)
}

func Log(name string, value interface{}) {
	fmt.Fprintf(os.Stderr, "%s=%+v\n", name, value)
}

func ExampleIo() {
	io := NewIo()
	defer io.Flush()
	a := make([]int, 0, 3)
	a[0], a[1], a[2] = io.NextInt(), io.NextInt(), io.NextInt()
	io.Println(a)
	io.PrintIntSlice(a)
	Log("io", a)
}

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <vector>

using namespace std;

struct edge {int from, to, dist;};

const int INF = 99999;

int Dijkstra(const vector<edge>& es, int n, int s, int t){
	int* cal_graph = new int[n*n];
	int* d = new int[n];
	bool* used= new bool[n];
	int dist;
	for(int j=0; j<n*n; j++){cal_graph[j]=INF;}
	for(int j=0; j<n; j++){cal_graph[j*n+j]=0;}
	for(int j=0; j<es.size(); j++){ cal_graph[ ((&es[j])->from)*n + (&es[j])->to ] = (&es[j])->dist;}

	fill(d,d+n, INF); fill(used,used+n,false); d[s]=0;
	while(true){
		int v = -1;
		for(int u=0; u<n; u++){ if(!used[u] && (v==-1 || d[u]<d[v])){v=u;}}
		if(v==-1){ break;}
		used[v]=true;
		for(int u=0; u<n; u++){ d[u] = min(d[u],d[v]+cal_graph[v*n+u]);}
	}
	dist = d[t];

	delete[] cal_graph;
	delete[] d;

	return dist;
}

int main()
{
	int w, h, ans;

	while(true){
		cin >> w >> h;
		if(w==0 && h==0){return 0;}
		int g;
		vector<edge> es;
		edge e;

		for(int i=0; i<h; i++){
			for(int j=0; j<w-1; j++){
				cin >> g;
				if(g==0){
					(e.from)=i*w+j; (e.to)=i*w+j+1; (e.dist)=1; es.push_back(e);
					(e.from)=i*w+j+1; (e.to)=i*w+j; (e.dist)=1; es.push_back(e);
				}
			}
			if(i!=(h-1)){
				for(int j=0; j<w; j++){
					cin >> g;
					if(g==0){
						(e.from)=i*w+j; (e.to)=i*w+j+w; (e.dist)=1; es.push_back(e);
						(e.from)=i*w+j+w; (e.to)=i*w+j; (e.dist)=1; es.push_back(e);
					}
				}			
			}
		}

		ans = INF; ans = min(ans,Dijkstra(es, w*h, 0, w*h-1));
		if(ans!=INF){cout << ans+1 << endl;}
		else{cout << 0 << endl;}
	}
}

C++: #include<iostream>
#include<algorithm>
#include<vector>
#include<queue>

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

int main(){

    while(1){
        int w, h;
        cin>> w>> h;
        if(!(w||h)) break;

        int maze[2*h-1][w*2-1];
        for(int i=0; i<2*h-1; i++){
            for(int j=0; j<w*2-1; j++){
                if(i%2==0&&j%2==0){
                    maze[i][j]=0;// point
                }else if((i+j)%2==0){
                    maze[i][j]=1;// intersection
                }else{

                }
            }
        }
        for(int i=0; i<2*h-1; i++){
            if(i%2==0){
                for(int j=0; j<w-1; j++){
                    int a;
                    cin>> a;
                    maze[i][2*j+1]=a;
                }
            }else{
                for(int j=0; j<w; j++){
                    int a;
                    cin>> a;
                    maze[i][2*j]=a;
                }
            }
        }

//        for(int i=0; i<2*h-1; i++){
//            for(int j=0; j<w*2-1; j++){
//                cout<< maze[i][j];
//            }cout<< endl;
//        }

        int dx[]={0, 0, -1, 1};
        int dy[]={1, -1, 0, 0};
        int d[h][w];
        const int inf=1e8;
        for(int i=0; i<h; i++){
            for(int j=0; j<w; j++){
                d[i][j]=inf;
            }
        }
        queue<pii> Q;
        Q.push(make_pair(0, 0));
        d[0][0]=0;
        while(!Q.empty()){
            pii p=Q.front(); Q.pop();
            if(p.first==2*h-2&&p.second==2*w-2){
                cout<< d[h-1][w-1]+1<< endl;
                break;
            }
            for(int i=0; i<4; i++){
                int y=p.first+dy[i];
                int x=p.second+dx[i];
                int Y=y+dy[i];
                int X=x+dx[i];
                if(!(0<=Y&&Y<2*h-1&&0<=X&&X<2*w-1)) continue;
                if(maze[y][x]) continue;
                if(d[Y/2][X/2]>d[p.first/2][p.second/2]+1){
                    d[Y/2][X/2]=d[p.first/2][p.second/2]+1;
                    Q.push(pii(Y, X));
                }
            }
        }
        
        if(d[h-1][w-1]==inf){
            cout<< 0<< endl;
        }
    }

    return 0;
}