/***二叉树节点的定义。*functionTreeNode(val,left,right){*this.val=(val===undefined?0:val)*this.left=(left===undefined?null:left)*this.right=(right===undefined?null:right)*}*//***@param{TreeNode}root*@return{number}*/varfindBottomLeftValue=function(root){letres=null//使用层序遍历letlayer=[]//当前层layer.push(root)//将根节点存为第一层while(layer.length){letlen=layer.length;//当前层数for(leti=0;i
