Why its not printing kth level

#1
#2

Is your tree getting built correctly ?

#3 
#include<iostream>
using namespace std;
class node{
public:
int data;
node *left;
node *right;
node(int d){
    data=d;
    left=NULL;
    right=NULL;
}
};
node * buildtree(){
    int d;
    cin>>d;
    if(d==-1)
    return NULL;
    node *root=new node(d);
    root->left=buildtree();
    root->right=buildtree();
    return root;
}
void printKthlevel(node *root,int k){
    if(root==NULL)
     return;
if(k==1){
 cout<<root->data<<" ";

}
printKthlevel(root->left,k-1);
printKthlevel(root->right,k-1);
return;
}
int main(){
    node *root=buildtree();
    printKthlevel(root,2);
}

Your tree was not getting built properly . I made some changes and now it is working properly.