Time Cost

6min51s

Code

/**
 * 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 diameter = 0;
    int diameterOfBinaryTree(TreeNode* root) {
        getMaxLength(root);
        return diameter;
    }

    int getMaxLength(TreeNode* root) {
        int llength = 0, rlength = 0, result = 0;
        if (root->left != nullptr) {
            llength = getMaxLength(root->left) + 1;
        }
        if (root->right != nullptr) {
            rlength = getMaxLength(root->right) + 1;
        }
        diameter = max(diameter, llength+rlength);
        return max(llength, rlength);
    }
};