problems

Untitled

notes

binary tree & BST

binary tree / n-ary tree

definition

// Definition for a binary tree node
struct TreeNode {
		int val;
		TreeNode* left;
		TreeNode* right;
		TreeNode() : val(0), left(nullptr), right(nullptr) {}
		TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
		TreeNode(int x, TreeNode* left, TreeNode* right) : val(x), left(left), right(right) {}
};

traversal:

inorder / preorder / postorder / levelorder

property

modification & construction