Diameter of Binary Tree
Problem Statement - link #
Given the root of a binary tree, return 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.
The length of a path between two nodes is represented by the number of edges between them.
Examples #
Example 1:
Input: root = [1,2,3,4,5]
Output: 3
Explanation: 3 is the length of the path [4,2,1,3] or [5,2,1,3].
Example 2:
Input: root = [1,2]
Output: 1
Constraints #
- The number of nodes in the tree is in the range
[1, 10^4]. -100 <= Node.val <= 100
Solutions #
/**
* 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) {}
* };
*/
class Solution {
public:
int d;
int findHeight(TreeNode* node){
if(!node) return 0;
int left = findHeight(node->left);
int right = findHeight(node->right);
d = max(d,left+right);
return max(left, right)+1;
}
int diameterOfBinaryTree(TreeNode* root) {
d = 0;
findHeight(root);
return d;
}
};