BST insertion and searching

#include<bits/stdc++.h>
using namespace std;
#define endl "\n";
typedef struct tree
{
    int number;
    struct tree *leftChild;
    struct tree *rightChild;
}node;
node *root = NULL;
void insertNode(int value)
{
    node *tempNode;
    node *currentNode=NULL;
    node *parentNode=NULL;
    tempNode = (node *) malloc (sizeof(node));
    tempNode->number=value;
    if(root==NULL)
    {
        root=tempNode;
    }
    else
    {
        currentNode=root;
        while(1)
        {
            parentNode=currentNode;
            if(parentNode->number>value)
            {
                currentNode=parentNode->leftChild;
                if(currentNode==NULL)
                {
                    parentNode->leftChild=tempNode;
                    return;
                }
            }
            else
            {
                currentNode=parentNode->rightChild;
                if(currentNode==NULL)
                {
                    parentNode->rightChild=tempNode;
                    return;
                }
            }
        }
    }
}
bool BST(int item)
{
    node *currentNode=root;
    int flag=0;
    while(1)
    {
        if(currentNode->number==item)
        {
            return true;
        }
        else if(currentNode->number<item)
        currentNode=currentNode->rightChild;
        else
        currentNode=currentNode->leftChild;
        if(currentNode==NULL)
        return false;
    }
}
int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int n;
    cin>>n;
    while(n--)
    {
        int a;
        cin>>a;
        insertNode(a);
    }
    cout<<"Insertion done"<<endl;
    int item;
    cin>>item;
    if(BST(item))
    {
        cout<<item<<" is found"<<endl;
    }
    else
    {
        cout<<item<<" is not found"<<endl;
    }
}