28.md

Binary Tree to CDLL

void inorder(Node* root,vector<int>&ans)
{
    if(root==NULL)
        return;
    
    inorder(root->left,ans);
    ans.push_back(root->data);
    inorder(root->right,ans);
}
class Solution
{
    
  public:

    Node *bTreeToCList(Node *root)
    {
    //add code here.
    
    if(root==NULL)
        return NULL;
    
    vector<int> ans;
    inorder(root,ans);
    
    Node* dummy=newNode(0);
    Node* p=dummy,*pre=NULL;
    
    for(auto num:ans)
    {
        p->right=newNode(num);
        p=p->right;
        p->left=pre;
        
        pre=p;
    }
    
    p->right=dummy->right;
    dummy->right->left=p;
    
    
    return dummy->right;
    
    }
};