LCAinBST.cpp

struct Node
{
    int data;
    struct  Node*left;
    struct Node*right;
    Node(int x){
        data=x;
        left=right=NULL;
    }
};
class Solution
{
    public:
    //Function to return the lowest common ancestor in a Binary Tree.
    Node* lca(Node* root ,int n1 ,int n2 )
    {
       //Your code here 
       
       if(root==NULL){
           return NULL;
       }
       if(root->data==n1 || root->data==n2){
           return root;
       }
      Node*leftAns=lca(root->left,n1,n2);
      Node*rightAns=lca(root->right,n1,n2);
      if(leftAns==NULL && rightAns==NULL){
          return NULL;
      }
      else if(leftAns!=NULL && rightAns==NULL){
          return leftAns;
      }
      else if(leftAns==NULL && rightAns!=NULL){
         return rightAns; 
      }
      else if(leftAns!=NULL && rightAns!=NULL){
          return root;
      }
       
      }
    
};