DiameterOfBinaryTree.c++

/**
 * 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 height(TreeNode *root)
    {
        if(root==NULL)
        {
            return 0;
        }
        int l=height(root->left);
        int r=height(root->right);
        if(l>r)
        {
            return l+1;
        }
        return r+1;
    }
    int diameterOfBinaryTree(TreeNode* root) 
    {
        if(root==NULL)
        {
            return 0;
        }
        int lh=height(root->left);
        int rh=height(root->right);
        int ld=diameterOfBinaryTree(root->left);
        int rd=diameterOfBinaryTree(root->right);
        int height=lh+rh;
        int diameter;
        if(ld>rd)
        {
            diameter=ld;
        }
        else
        {
            diameter=rd;
        }
        if(height>diameter)
        {
            return height;
        }
        return diameter;
    }
};