# Binary Tree

- [1. Traversal](/algo/binary-tree/1.-traversal.md)
- [Binary Tree Preorder Traversal](/algo/binary-tree/1.-traversal/binary-tree-preorder-traversal.md): ID: 144; easy
- [Binary Tree Inorder Traversal](/algo/binary-tree/1.-traversal/binary-tree-inorder-traversal.md): ID: 94; easy
- [Binary Tree Postorder Traversal](/algo/binary-tree/1.-traversal/binary-tree-postorder-traversal.md): ID: 145; easy
- [Construct Binary Tree from Inorder and Postorder Traversal](/algo/binary-tree/1.-traversal/construct-binary-tree-from-inorder-and-postorder-traversal.md): ID: 72; medium; 中序遍历和后序遍历树构造二叉树
- [Minimum Depth of Binary Tree](/algo/binary-tree/1.-traversal/minimum-depth-of-binary-tree.md): ID: 111; easy
- [Find Leaves of Binary Tree](/algo/binary-tree/1.-traversal/find-leaves-of-binary-tree.md): ID: 650; medium; 二叉树叶子顺序遍历
- [Reconstruct Itinerary](/algo/binary-tree/1.-traversal/reconstruct-itinerary.md): ID: 1288; medium;
- [2. Classical Questions](/algo/binary-tree/2.-classical-questions.md)
- [Maximum Depth of Binary Tree](/algo/binary-tree/2.-classical-questions/maximum-depth-of-binary-tree.md): ID: 104; easy
- [Average of Levels in Binary Tree](/algo/binary-tree/2.-classical-questions/average-of-levels-in-binary-tree.md): ID: 1115; easy; 二叉树每层的平均数
- [Binary Tree Leaf Sum](/algo/binary-tree/2.-classical-questions/binary-tree-leaf-sum.md): ID: 481; easy; 二叉树叶子节点之和
- [Invert Binary Tree](/algo/binary-tree/2.-classical-questions/invert-binary-tree.md): ID: 226; easy
- [Binary Tree Path Sum](/algo/binary-tree/2.-classical-questions/binary-tree-path-sum.md): ID: 376; easy;  二叉树的路径和
- [Binary Tree Path Sum II](/algo/binary-tree/2.-classical-questions/binary-tree-path-sum-ii.md): ID: 246; medium; 二叉树的路径和 II
- [Binary Tree Path Sum III](/algo/binary-tree/2.-classical-questions/binary-tree-path-sum-iii.md): ID: 472; hard; 二叉树的路径和 III
- [Clone Binary Tree](/algo/binary-tree/2.-classical-questions/clone-binary-tree.md): ID: 375; medium; 克隆二叉树
- [Sum Root to Leaf Numbers](/algo/binary-tree/2.-classical-questions/sum-root-to-leaf-numbers.md): ID: 1353; medium; 根节点到叶节点求和
- [Binary Tree Level Sum](/algo/binary-tree/2.-classical-questions/binary-tree-level-sum.md): ID: 482; easy; 二叉树的某层节点之和
- [Binary Tree Paths](/algo/binary-tree/2.-classical-questions/binary-tree-paths.md): ID: 257; easy
- [3. Binary Search Tree](/algo/binary-tree/3.-binary-search-tree.md)
- [Insert Node in a Binary Search Tree](/algo/binary-tree/3.-binary-search-tree/insert-node-in-a-binary-search-tree.md): ID: 85; easy; 在二叉查找树中插入节点
- [Remove Node in Binary Search Tree](/algo/binary-tree/3.-binary-search-tree/remove-node-in-binary-search-tree.md): ID: 87; hard; 删除二叉查找树的节点
- [Validate Binary Search Tree](/algo/binary-tree/3.-binary-search-tree/validate-binary-search-tree.md): ID: 98; medium; 验证二叉查找树
- [Trim a Binary Search Tree](/algo/binary-tree/3.-binary-search-tree/trim-a-binary-search-tree.md): ID: 701; medium; 修剪二叉搜索树
- [Search Range in Binary Search Tree](/algo/binary-tree/3.-binary-search-tree/search-range-in-binary-search-tree.md): ID: 11; medium; 二叉查找树中搜索区间
- [Inorder Successor in BST](/algo/binary-tree/3.-binary-search-tree/inorder-successor-in-bst.md): ID: 448; medium; 二叉查找树的中序后继
- [Binary Search Tree Iterator](/algo/binary-tree/3.-binary-search-tree/binary-search-tree-iterator.md): ID: 86; hard; 二叉查找树迭代器
- [Recover Binary Search Tree](/algo/binary-tree/3.-binary-search-tree/recover-binary-search-tree.md): ID: 691; medium; 恢复二叉搜索树
- [4. Divide and Conquer](/algo/binary-tree/4.-divide-and-conquer.md)
- [Balanced Binary Tree](/algo/binary-tree/4.-divide-and-conquer/balanced-binary-tree.md): ID: 110; easy
- [Minimum Subtree](/algo/binary-tree/4.-divide-and-conquer/minimum-subtree.md): ID: 596; easy; 最小子树
- [Subtree with Maximum Average](/algo/binary-tree/4.-divide-and-conquer/subtree-with-maximum-average.md): ID: 597; easy
- [Maximum Subtree](/algo/binary-tree/4.-divide-and-conquer/maximum-subtree.md): ID: 628; easy
- [Lowest Common Ancestor of a Binary Tree](/algo/binary-tree/4.-divide-and-conquer/lowest-common-ancestor-of-a-binary-tree.md): ID: 88; medium
- [Lowest Common Ancestor II](/algo/binary-tree/4.-divide-and-conquer/lowest-common-ancestor-ii.md): ID: 474; easy
- [Lowest Common Ancestor III](/algo/binary-tree/4.-divide-and-conquer/lowest-common-ancestor-iii.md): ID: 578; medium
- [Binary Tree Maximum Path Sum II](/algo/binary-tree/4.-divide-and-conquer/binary-tree-maximum-path-sum-ii.md): ID: 475; medium
- [Binary Tree Maximum Path Sum](/algo/binary-tree/4.-divide-and-conquer/binary-tree-maximum-path-sum.md): ID: 94; medium
- [Path Sum III](/algo/binary-tree/4.-divide-and-conquer/path-sum-iii.md): ID: 437; medium
- [Convert Sorted Array to Binary Search Tree](/algo/binary-tree/convert-sorted-array-to-binary-search-tree.md): ID; 108; easy
- [Path Sum](/algo/binary-tree/path-sum.md): ID: 112; easy
- [Lowest Common Ancestor of a Binary Search Tree](/algo/binary-tree/lowest-common-ancestor-of-a-binary-search-tree.md): ID: 235; easy
- [Sum of Left Leaves](/algo/binary-tree/sum-of-left-leaves.md): ID: 404; easy
- [Minimum Absolute Difference in BST](/algo/binary-tree/minimum-absolute-difference-in-bst.md): ID: 530; easy
- [Minimum Distance Between BST Nodes](/algo/binary-tree/minimum-distance-between-bst-nodes.md): ID: 783; easy
- [Convert Sorted List to Binary Search Tree](/algo/binary-tree/convert-sorted-list-to-binary-search-tree.md): ID: 109; medium
- [Range Sum of BST](/algo/binary-tree/range-sum-of-bst.md): ID: 938; easy
- [Kth Smallest Element in a BST](/algo/binary-tree/kth-smallest-element-in-a-bst.md): ID: 230; medium
- [Find Largest Value in Each Tree Row](/algo/binary-tree/find-largest-value-in-each-tree-row.md): ID: 515; medium