题解 | #走迷宫#

var lines = []
while(line = readline()) {
    lines.push(line)
}
let line1=lines[0].split(' ');
var n=Number(line1[0]),m=Number(line1[1]);
let line2=lines[1].split(' ');
var map=new Array(n);
for(let i=0;i<n;i++){
    map[i]=lines[i+2].split('');
}
let target = false;
map[Number(line2[0])-1][Number(line2[1])-1]=0;
function bfs(queue) {
    const nextQueute = [];
    if(queue.length === 0) return;
    if(target) return;
    let dep =map[queue[0][0]][queue[0][1]];
    let dx=[0, 0 ,1 ,-1],dy=[1,-1,0,0];
    for(let j=0;j<queue.length;j++) {
        for(let i = 0;i<4;i++) {
            let ni=dx[i]+queue[j][0],nj=dy[i]+queue[j][1];
            if(ni<0 || ni>=n || nj<0 || nj>=m) continue;
            if(map[ni][nj] === '.') {
                map[ni][nj]=dep+1;
                if(ni === Number(line2[2])-1 && nj === Number(line2[3])-1) target = true;
                nextQueute.push([ni,nj]);
            }
        }
    }
    if(nextQueute.length && !target) bfs(nextQueute);
}
let queee=[[Number(line2[0])-1,Number(line2[1])-1]];
bfs(queee);
if(map[Number(line2[2])-1][Number(line2[3])-1] !== '.' && map[Number(line2[2])-1][Number(line2[3])-1] !== '*') {
    print(map[Number(line2[2])-1][Number(line2[3])-1])
}else{
    print(-1)
}