Leetcode 543 Solution

This article provides solution to leetcode question 543 (diameter-of-binary-tree)

https://leetcode.com/problems/diameter-of-binary-tree

Solution

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    int diameterOfBinaryTree(TreeNode* root, int& depth)
    {
        if (root == NULL)
        {
            depth = 0;
            return 0;
        }

        int left_depth;
        int left_diameter = diameterOfBinaryTree(root->left, left_depth);

        int right_depth;
        int right_diameter = diameterOfBinaryTree(root->right, right_depth);

        depth = max(left_depth, right_depth) + 1;

        int diameter = max(left_diameter, right_diameter);
        return max(diameter, left_depth + right_depth);
    }

    int diameterOfBinaryTree(TreeNode* root) {
        int depth;
        return diameterOfBinaryTree(root, depth);
    }
};