543. Diameter of Binary Tree
Given a binary tree, you need to compute the length of the diameter of the tree. The diameter of a binary tree is the length of the longestpath between any two nodes in a tree. This path may or may not pass through the root.
Example:
Given a binary tree
1 / \ 2 3 / \ 4 5
Return 3, which is the length of the path [4,2,1,3] or [5,2,1,3].
题目含义:求二叉树的直径,并告诉了我们直径就是两点之间的最远距离。这条直径可以不包含根节点
1 private int maxLength = 0; 2 private int maxDepth(TreeNode root) 3 { 4 if (root == null)return 0; 5 int leftMaxDepth = maxDepth(root.left); 6 int rightMaxDepth = maxDepth(root.right); 7 maxLength = Math.max(maxLength,leftMaxDepth+rightMaxDepth); 8 return Math.max(leftMaxDepth,rightMaxDepth)+1; 9 } 10 public int diameterOfBinaryTree(TreeNode root) { 11 maxDepth(root); 12 return maxLength; 13 }