eric 凯

var isValidBST = function(root) { let cur = root let track = [] let arr = [] while(cur || track.length > 0){ while(cur){ track.push(cur) cur = cur.left } cur =...

递归算法，先递归遍历左节点，必须小于max；再递归遍历右节点，必须大于min； var isValidBST = function(root,min=-Infinity,max=Infinity) { if(root == null) return true if(root.val = max) return false return isValidBST(root.left,min,root.val) && isValidBST(root.right,root.val,max) };