import java.util.Deque;
import java.util.LinkedList;
class node{
int x;
int y;
}
class Solution{
private int dir[][]=new int[][] {{0,-1},{-1,0},{0,1},{1,0}};
private node parentx[][];
private int Count[][];
private boolean used[][];
private node start=new node();
private node end=new node();
private Deque<node> queue=new LinkedList<node>();
private node temp;
private boolean flag=false;
public boolean isCheckMove(String[] map,node start) {
return start.x>=0&&start.x<map.length&&start.y>=0&&start.y<map[start.x].length();
}
public boolean printPath(String[] map) {
while(parentx[temp.x][temp.y].x!=temp.x||parentx[temp.x][temp.y].y!=temp.y) {
System.out.print(map[temp.x].charAt(temp.y)+"->");
temp=parentx[temp.x][temp.y];
}
System.out.println(map[temp.x].charAt(temp.y));
return true;
}
public int dfs(String[] map,node start) {
queue.offer(start);
used[start.x][start.y]=true;
Count[start.x][start.y]=1;
while(!queue.isEmpty()) {
start=queue.pop();
for(int i=0;i<4;++i) {
temp=new node();
temp.x=start.x+dir[i][0];
temp.y=start.y+dir[i][1];
if(temp.x==end.x&&temp.y==end.y) {
flag=true;
queue.addLast(temp);
parentx[temp.x][temp.y]=start;
Count[temp.x][temp.y]=Count[start.x][start.y]+1;
used[temp.x][temp.y]=true;
break;
}
if(isCheckMove(map,temp)&&!used[temp.x][temp.y]) {
queue.addLast(temp);
parentx[temp.x][temp.y]=start;
Count[temp.x][temp.y]=Count[start.x][start.y]+1;
used[temp.x][temp.y]=true;
}
}
if(flag) {
break;
}
}
return Count[temp.x][temp.y];
}
public boolean nums(String map[]) {
queue.clear();
parentx=new node[map.length][map[0].length()];
Count=new int[map.length][map[0].length()];
used=new boolean[map.length][map[0].length()];
for(int i=0;i<map.length;++i) {
for(int j=0;j<map[i].length();++j) {
used[i][j]=false;
Count[i][j]=0;
node tmp=new node();
tmp.x=i;
tmp.y=j;
parentx[i][j]=tmp;
if(map[i].charAt(j)=='#') {
end.x=i;
end.y=j;
}
if(map[i].charAt(j)=='@') {
start.x=i;
start.y=j;
}
}
}
System.out.println(dfs(map,start));
printPath(map);
return true;
}
}
public class First{
public static void main(String[] args) {
Solution space = new Solution();
String map[]= {"****","@***","&&&&","&&&&","&#**"};
space.nums(map);
for(String str:map) {
System.out.println(str);
}
}
}