<p>Given the <code>root</code> of a binary tree, return <em>the lowest common ancestor of its deepest leaves</em>.</p>

<p>Recall that:</p>

<ul>
	<li>The node of a binary tree is a leaf if and only if it has no children</li>
	<li>The depth of the root of the tree is <code>0</code>. if the depth of a node is <code>d</code>, the depth of each of its children is <code>d + 1</code>.</li>
	<li>The lowest common ancestor of a set <code>S</code> of nodes, is the node <code>A</code> with the largest depth such that every node in <code>S</code> is in the subtree with root <code>A</code>.</li>
</ul>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://s3-lc-upload.s3.amazonaws.com/uploads/2018/07/01/sketch1.png" style="width: 600px; height: 510px;" />
<pre>
<strong>Input:</strong> root = [3,5,1,6,2,0,8,null,null,7,4]
<strong>Output:</strong> [2,7,4]
<strong>Explanation:</strong> We return the node with value 2, colored in yellow in the diagram.
The nodes coloured in blue are the deepest leaf-nodes of the tree.
Note that nodes 6, 0, and 8 are also leaf nodes, but the depth of them is 2, but the depth of nodes 7 and 4 is 3.</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> root = [1]
<strong>Output:</strong> [1]
<strong>Explanation:</strong> The root is the deepest node in the tree, and it&#39;s the lca of itself.
</pre>

<p><strong class="example">Example 3:</strong></p>

<pre>
<strong>Input:</strong> root = [0,1,3,null,2]
<strong>Output:</strong> [2]
<strong>Explanation:</strong> The deepest leaf node in the tree is 2, the lca of one node is itself.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li>The number of nodes in the tree will be in the range <code>[1, 1000]</code>.</li>
	<li><code>0 &lt;= Node.val &lt;= 1000</code></li>
	<li>The values of the nodes in the tree are <strong>unique</strong>.</li>
</ul>

<p>&nbsp;</p>
<p><strong>Note:</strong> This question is the same as 865: <a href="https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes/" target="_blank">https://leetcode.com/problems/smallest-subtree-with-all-the-deepest-nodes/</a></p>

class Solution {
public:
vector<vector<int>> levelOrder(TreeNode* root) {
        vector<TreeNode*> queue;
        vector<vector<int>> ans;

        if (!root) {
            return {};
        }

        queue.push_back(root);

        while (!queue.empty()) {
            int size = queue.size();
            vector<int> curr;

            for (int i = 0; i < size; i++) {
                TreeNode* node = queue[0];
                queue.erase(queue.begin());

                curr.push_back(node->val);

                if (node->left) queue.push_back(node->left);
                if (node->right) queue.push_back(node->right);
            }

            ans.push_back(curr);
        }

        return ans;
    }

    int find(TreeNode* root , vector<int> &a , int t){
   if (root == nullptr) return 0;  
    if (root->val == t) return 1;  
     
    a.push_back(0);               
    if (find(root->left, a, t)) return 1;
    a.pop_back();                  

    a.push_back(1);                 
    if (find(root->right, a, t)) return 1;
    a.pop_back();                 

    return 0; 
}




    TreeNode* lcaDeepestLeaves(TreeNode* root) {
        vector<vector<int>> lvl = levelOrder(root);
        vector<int> last = lvl.back();
        vector<vector<int>> dir;

        for(int i = 0 ; i<last.size() ; i++){  

            vector<int> cur;
            find(root,cur,last[i]);
            dir.push_back(cur);
            
        }
        int ans;
        int br = 1;

    for(int i = 0 ; i < dir[0].size() ; i++){
        for(int j = 0 ; j < dir.size()-1 ; j++){
            if(dir[j][i]!=dir[j+1][i]){br=0;ans = i;break;}
        }
        if(br==0){break;}
    }


    TreeNode* answer = root;

    for(int i = 0 ; i < ans ; i++){
        if(dir[0][i]==0){answer = answer->left;}
        else{answer = answer->right;}
    }
    return answer;










        
    }
};
23000