/**
knakul853
 */
class Solution {
public:
    TreeNode* lowestCommonAncestor(TreeNode* root, TreeNode* p, TreeNode* q) {

        if(!root || p == root || q == root ) return root;

        auto left = lowestCommonAncestor(root->left, p, q);
        auto right = lowestCommonAncestor( root->right, p, q);

        if(left && right) return root;

        return left ? left : right;


    }
};