Go: package main

import (
	"bufio"
	"fmt"
	"math"
	"os"
	"strconv"
)

func configure(scanner *bufio.Scanner) {
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
}
func getNextString(scanner *bufio.Scanner) string {
	scanned := scanner.Scan()
	if !scanned {
		panic("scan failed")
	}
	return scanner.Text()
}
func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}
func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}
func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}
func main() {
	fp := os.Stdin
	wfp := os.Stdout
	extra := 0
	if os.Getenv("I") == "IronMan" {
		fp, _ = os.Open(os.Getenv("END_GAME"))
		extra = 100
	}
	scanner := bufio.NewScanner(fp)
	configure(scanner)
	writer := bufio.NewWriter(wfp)
	defer func() {
		r := recover()
		if r != nil {
			fmt.Fprintln(writer, r)
		}
		writer.Flush()
	}()
	solve(scanner, writer)
	for i := 0; i < extra; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
}
func solve(scanner *bufio.Scanner, writer *bufio.Writer) {
	dy := [4]int{-1, 0, 0, 1}
	dx := [4]int{0, -1, 1, 0}
	for {
		h := getNextInt(scanner)
		w := getNextInt(scanner)
		if h == 0 {
			break
		}
		grid := makeGrid(h, w)
		a := [2]int{}
		b := [2]int{}
		for i := 0; i < h; i++ {
			s := getNextString(scanner)
			for j := 0; j < w; j++ {
				if s[j] == '#' {
					grid[i][j] = math.MaxInt32
					continue
				}
				if s[j] == 'A' {
					a[0] = i
					a[1] = j
					continue
				}
				if s[j] == 'B' {
					b[0] = i
					b[1] = j
				}
				grid[i][j] = math.MaxInt32 - 1
			}
		}
		q := make([][2]int, 0)
		q = append(q, a)
		for len(q) > 0 {
			p := q[0]
			q = q[1:]
			for i := 0; i < 4; i++ {
				yy := p[0] + dy[i]
				xx := p[1] + dx[i]
				if yy == a[0] && xx == a[1] {
					continue
				}
				if yy < 0 || yy >= h {
					continue
				}
				if xx < 0 || xx >= w {
					continue
				}
				if grid[yy][xx] == math.MaxInt32 {
					continue
				}
				if grid[yy][xx] <= grid[p[0]][p[1]]+1 {
					continue
				}
				grid[yy][xx] = grid[p[0]][p[1]] + 1
				q = append(q, [2]int{yy, xx})
			}
		}
		move := getNextString(scanner)
		i := 0
		m := len(move)
		for {
			if i > 400 {
				fmt.Fprintln(writer, "impossible")
				break
			}
			if grid[b[0]][b[1]] <= i {
				fmt.Fprintln(writer, fmt.Sprintf("%d %d %d", i, b[0], b[1]))
				break
			}
			switch move[i%m] {
			case '8':
				if b[0] > 0 {
					b[0]--
				}
			case '6':
				if b[1]+1 < w {
					b[1]++
				}
			case '4':
				if b[1] > 0 {
					b[1]--
				}
			case '2':
				if b[0]+1 < h {
					b[0]++
				}
			}
			i++
		}
	}
}
func makeGrid(h, w int) [][]int {
	index := make([][]int, h, h)
	data := make([]int, h*w, h*w)
	for i := 0; i < h; i++ {
		index[i] = data[i*w : (i+1)*w]
	}
	return index
}

C++: #include <iostream>
#include <cstdio>
#include <cmath>
#include <vector>
#include <map>
#include <stack>
#include <queue>
#include <algorithm>
#include <set>

#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define REP(i,j) FOR(i,0,j)
#define mp std::make_pair

const int INF = 1 << 24;
// S N E W
const int dx[8] = {0, 0, 1, -1, 1, 1, -1, -1}, dy[8] = {1, -1, 0, 0, 1, -1, 1, -1};

typedef unsigned long long ull;
typedef std::pair<int,int> P;
typedef std::pair<int,P> State;

int H, W;
char map[20][20];
P a, b;
int d[20][20];
std::string pattern;

void bfs(){
    REP(i, 20){
        REP(j, 20){
            d[i][j] = INF;
        }
    }

    std::queue<State> q;
    q.push(mp(0, a));
    d[a.second][a.first] = 0;

    while(!q.empty()){
        State s = q.front(); q.pop();
        int cost = s.first;
        P p = s.second;

        if(d[p.second][p.first] < cost){continue;}
        
        REP(i, 4){
            int nx = p.first + dx[i],
                ny = p.second + dy[i];
            if(0 <= nx && nx < W &&
               0 <= ny && ny < H &&
               d[ny][nx] > cost + 1 && map[ny][nx] == '.'){
                q.push(mp(cost+1, mp(nx, ny)));
                d[ny][nx] = cost + 1;
            }
        }
    }
}

State buster(){
    std::string table = "2864";
    int index = 0, t = 1;
    while(t <= 400){
        REP(i, 4){
            if(pattern[index] == table[i]){
                int nx = b.first + dx[i], ny = b.second + dy[i];
                if(0 <= nx && nx < W &&
                   0 <= ny && ny < H){
                    b = mp(nx, ny);
                }
                break;
            }
        }

        if(t >= d[b.second][b.first]){
            return mp(t, b);
        }

        index = (index + 1) % pattern.size();
        t++;
    }

    return mp(t, mp(-1, -1));
}

int main(){
    while(std::cin >> H >> W, H){
        REP(i, H){
            REP(j, W){
                std::cin >> map[i][j];
                if(map[i][j] == 'A'){
                    a = mp(j, i);
                    map[i][j] = '.';
                }else if(map[i][j] == 'B'){
                    b = mp(j, i);
                    map[i][j] = '.';
                }
            }
        }

        std::cin >> pattern;

        bfs();

        // REP(i, H){
        //     REP(j, W){
        //         printf("%d, ", d[i][j]);
        //     }
        //     puts("");
        // }

        State res = buster();
        if(res.first > 400){
            puts("impossible");
        }else{
            printf("%d %d %d\n", res.first, res.second.second, res.second.first);
        }
    }
}

C++: #include <queue>
#include <string>
#include <vector>
#include <iostream>
using namespace std;
int dir[] = { 0, 1, 0, -1 };
int H, W, dist[25][25]; string s[25], t;
int main() {
	while (cin >> H >> W, H) {
		int ax = -1, ay = -1, bx = -1, by = -1;
		for (int i = 0; i < H; i++) {
			cin >> s[i];
			for (int j = 0; j < W; j++) {
				if (s[i][j] == 'A') ax = i, ay = j;
				if (s[i][j] == 'B') bx = i, by = j;
			}
		}
		cin >> t;
		for (int i = 0; i < H; i++) {
			for (int j = 0; j < W; j++) {
				dist[i][j] = 999999999;
			}
		}
		queue<pair<int, int> > que; que.push(make_pair(ax, ay)); dist[ax][ay] = 0;
		while (!que.empty()) {
			pair<int, int> u = que.front(); que.pop();
			for (int i = 0; i < 4; i++) {
				int tx = u.first + dir[i], ty = u.second + dir[i ^ 1];
				if (0 <= tx && tx < H && 0 <= ty && ty < W && s[tx][ty] != '#' && dist[tx][ty] == 999999999) {
					dist[tx][ty] = dist[u.first][u.second] + 1;
					que.push(make_pair(tx, ty));
				}
			}
		}
		bool flag = false;
		for (int i = 0; i < 10000; i++) {
			if (dist[bx][by] <= i) {
				cout << i << ' ' << bx << ' ' << by << endl;
				flag = true; break;
			}
			int tx = bx, ty = by;
			if (t[i % t.size()] == '2') tx++;
			if (t[i % t.size()] == '4') ty--;
			if (t[i % t.size()] == '6') ty++;
			if (t[i % t.size()] == '8') tx--;
			if (0 <= tx && tx < H && 0 <= ty && ty < W) bx = tx, by = ty;
		}
		if (!flag) cout << "Impossible" << endl;
	}
	return 0;
}