题目
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 longest path 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.
答案
class Solution {
int max = 0;
public int diameterOfBinaryTree(TreeNode root) {
maxdepth(root);
return max;
}
public int maxdepth(TreeNode root) {
if(root == null) return 0;
int left = maxdepth(root.left);
int right = maxdepth(root.right);
max = Math.max(max, left + right);
return Math.max(left, right) + 1;
}
}
