Check if each internal node of a BST has exactly one child

#include<iostream>
using namespace std;
class Node{
  public:
      int data;
      Node *left,*right;
      Node(int key){
        data=key;
        left=right=NULL;
        }
  };

void Insert(Node **root_ref,int key){
  if(*root_ref==NULL){
    *root_ref=new Node(key);
    return;
    }
  if((*root_ref)->data<key)
    Insert(&((*root_ref)->right),key);
  else
     if((*root_ref)->data>key)
       Insert(&((*root_ref)->left),key);
  }

int HasOnlyOneChild(Node *root){
  if(root==NULL)
    return 1;
  if(root->left!=NULL && root->right!=NULL)
     return 0;
    return  HasOnlyOneChild(root->left)&& HasOnlyOneChild(root->right);
  }

int main(){
 Node *root=NULL;
 Insert(&root,5);
 Insert(&root,7);
 Insert(&root,4);
 Insert(&root,8);
 if(HasOnlyOneChild(root))
   cout<<"yes";
 else
   cout<<"no";
 return 0;
 }