* Definition for a binary tree node.
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
TreeNode* subtreeWithAllDeepest(TreeNode* root) {
int DL= depth(root->left);
int DR = depth(root->right);
return DL>DR? subtreeWithAllDeepest(root->left):subtreeWithAllDeepest(root->right);
int depth(TreeNode* root)
int dl = depth(root->left);
int dr = depth(root->right);
return dl>dr ? dl+1:dr+1;