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].
Note: The length of path between two nodes is represented by the number of edges between them.
计算树中任意两个节点之间的路径,要求路径最长
C++(12ms):
1 /** 2 * Definition for a binary tree node. 3 * struct TreeNode { 4 * int val; 5 * TreeNode *left; 6 * TreeNode *right; 7 * TreeNode(int x) : val(x), left(NULL), right(NULL) {} 8 * }; 9 */ 10 class Solution { 11 public: 12 int diameterOfBinaryTree(TreeNode* root) { 13 int res = 0 ; 14 maxDepth(root,res) ; 15 return res ; 16 17 } 18 19 int maxDepth(TreeNode* root , int& res){ 20 if (root == NULL) return 0 ; 21 int left = maxDepth(root->left,res) ; 22 int right = maxDepth(root->right,res) ; 23 res = max(res , left+right) ; 24 25 return 1 + max(left,right) ; 26 } 27 };