【攻克力扣200题--32】1091. 二进制矩阵中的最短路径

BFS,在宝宝的帮助下，顺利地写出了这题，开心

var shortestPathBinaryMatrix = function(grid) {
    if(grid[0][0]==1) return -1;
    let direction=[[1,1],[1,0],[1,-1],[0,1],[0,-1],[-1,1],[-1,0],[-1,-1]];
    let queue=[];
    let m=grid.length,n=grid[0].length;
    let pathLength=0;
    queue.push([0,0]);
    while(queue.length>0){
         var size=queue.length;
         pathLength++;
         while(size-->0){
             var cur=queue.shift();
             var cr=cur[0],cc=cur[1];
             if(cr==m-1&&cc==n-1) return pathLength;
             for(var i=0;i<8;i++){
                 var nr=cr+direction[i][0],nc=cc+direction[i][1];
                 if(nr<0||nc<0||nr>=m||nc>=n||grid[nr][nc]==1) continue;
                 grid[nr][nc]=1;
                 queue.push([nr,nc]);
             }
            }
          }
      return -1;
};