/**
* 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 ans;
int dfs(TreeNode* now){
int L = 0;
if(now->left != NULL) L = dfs(now->left);
int R = 0;
if(now->right != NULL) R = dfs(now->right);
ans = max(ans,L+R+1);
return max(L,R)+1;
}
int diameterOfBinaryTree(TreeNode* root) {
ans = 1;
if(root != NULL) dfs(root);
return ans;
}
};