ceil_of_aBST.c++

#include <bits/stdc++.h> 
/************************************************************

    Following is the TreeNode class structure:

    class BinaryTreeNode {
    public:
        T data;
        BinaryTreeNode<T> *left;
        BinaryTreeNode<T> *right;
        
        BinaryTreeNode(T data) {
            this->data = data;
            left = NULL;
            right = NULL;
        }
        
        ~BinaryTreeNode() {
            if (left) {
              delete left;
            }
            if (right) {
              delete right;
            }
        }
    };

************************************************************/
void solve(BinaryTreeNode<int> *node, int x, int&ans){
    if(node==NULL){
        return;
    }
    solve(node->left,x,ans);
    if(node->data>=x && ans==-1){
        ans=node->data;
    }
    solve(node->right,x,ans);
    return;
}
int findCeil(BinaryTreeNode<int> *node, int x){
    // Write your code here.
    int ans=-1;
    solve(node,x,ans);
    return ans;
}