codeparrot/xlcost-text-to-code huggingface dataset:
Find the sum of last n nodes of the given Linked List | C # implementation to find the sum of last ' n ' nodes of the Linked List ; A Linked list node ; function to insert a node at the beginning of the linked list ; allocate node ; put in the data ; link the old list to the new node ; move the head to point to the new node ; utility function to find the sum of last ' n ' nodes ; if n == 0 ; calculate the length of the linked list ; count of first ( len - n ) nodes ; just traverse the 1 st ' c ' nodes ; move to next node ; now traverse the last ' n ' nodes and add them ; accumulate node 's data to sum ; move to next node ; required sum ; Driver code ; create linked list 10.6 .8 .4 .12
using System ; class GFG { public class Node { public int data ; public Node next ; } ; static Node head ; static void push ( Node head_ref , int new_data ) { Node new_node = new Node ( ) ; new_node . data = new_data ; new_node . next = head_ref ; head_ref = new_node ; head = head_ref ; } static int sumOfLastN_NodesUtil ( Node head , int n ) { if ( n <= 0 ) return 0 ; int sum = 0 , len = 0 ; Node temp = head ; while ( temp != null ) { len ++ ; temp = temp . next ; } int c = len - n ; temp = head ; while ( temp != null && c -- > 0 ) { temp = temp . next ; } while ( temp != null ) { sum += temp . data ; temp = temp . next ; } return sum ; } public static void Main ( String [ ] args ) { push ( head , 12 ) ; push ( head , 4 ) ; push ( head , 8 ) ; push ( head , 6 ) ; push ( head , 10 ) ; int n = 2 ; Console . WriteLine ( " Sum ▁ of ▁ last ▁ " + n + " ▁ nodes ▁ = ▁ " + sumOfLastN_NodesUtil ( head , n ) ) ; } }
Merge two sorted linked lists |  ; Point to the last result pointer ; tricky : advance to point to the next " . next " field
Node SortedMerge ( Node a , Node b ) { Node result = null ; Node lastPtrRef = result ; while ( 1 ) { if ( a == null ) { lastPtrRef = b ; break ; } else if ( b == null ) { lastPtrRef = a ; break ; } if ( a . data <= b . data ) { MoveNode ( lastPtrRef , a ) ; } else { MoveNode ( lastPtrRef , b ) ; } lastPtrRef = ( ( lastPtrRef ) . next ) ; } return ( result ) ; }
Merge K sorted linked lists | Set 1 | C # program to merge k sorted arrays of size n each ; A Linked List node ; Utility function to create a new node . ; Function to print nodes in a given linked list ; The main function that takes an array of lists arr [ 0. . last ] and generates the sorted output ; Traverse form second list to last ; head of both the lists , 0 and ith list . ; Break if list ended ; Smaller than first element ; Traverse the first list ; Smaller than next element ; go to next node ; if last node ; Driver program to test above functions ; Number of linked lists ; an array of pointers storing the head nodes of the linked lists ; Merge all lists
using System ; public class Node { public int data ; public Node next ; public Node ( int key ) { data = key ; next = null ; } } public class GFG { static Node head ; static void printList ( Node node ) { while ( node != null ) { Console . Write ( node . data + " ▁ " ) ; node = node . next ; } Console . WriteLine ( ) ; } static Node mergeKLists ( Node [ ] arr , int last ) { for ( int i = 1 ; i <= last ; i ++ ) { while ( true ) { Node head_0 = arr [ 0 ] ; Node head_i = arr [ i ] ; if ( head_i == null ) break ; if ( head_0 . data >= head_i . data ) { arr [ i ] = head_i . next ; head_i . next = head_0 ; arr [ 0 ] = head_i ; } else { while ( head_0 . next != null ) { if ( head_0 . next . data >= head_i . data ) { arr [ i ] = head_i . next ; head_i . next = head_0 . next ; head_0 . next = head_i ; break ; } head_0 = head_0 . next ; if ( head_0 . next == null ) { arr [ i ] = head_i . next ; head_i . next = null ; head_0 . next = head_i ; head_0 . next . next = null ; break ; } } } } } return arr [ 0 ] ; } static public void Main ( ) { int k = 3 ; Node [ ] arr = new Node [ k ] ; arr [ 0 ] = new Node ( 1 ) ; arr [ 0 ] . next = new Node ( 3 ) ; arr [ 0 ] . next . next = new Node ( 5 ) ; arr [ 0 ] . next . next . next = new Node ( 7 ) ; arr [ 1 ] = new Node ( 2 ) ; arr [ 1 ] . next = new Node ( 4 ) ; arr [ 1 ] . next . next = new Node ( 6 ) ; arr [ 1 ] . next . next . next = new Node ( 8 ) ; arr [ 2 ] = new Node ( 0 ) ; arr [ 2 ] . next = new Node ( 9 ) ; arr [ 2 ] . next . next = new Node ( 10 ) ; arr [ 2 ] . next . next . next = new Node ( 11 ) ; head = mergeKLists ( arr , k - 1 ) ; printList ( head ) ; } }
Merge two sorted lists ( in | C # program to merge two sorted linked lists in - place . ; Function to create newNode in a linkedlist ; A utility function to print linked list ; Merges two given lists in - place . This function mainly compares head nodes and calls mergeUtil ( ) ; start with the linked list whose head data is the least ; Driver code ; 1.3 . 5 LinkedList created ; 0.2 . 4 LinkedList created
using System ; class GFG { public class Node { public int data ; public Node next ; } ; static Node newNode ( int key ) { Node temp = new Node ( ) ; temp . data = key ; temp . next = null ; return temp ; } static void printList ( Node node ) { while ( node != null ) { Console . Write ( " { 0 } ▁ " , node . data ) ; node = node . next ; } } static Node merge ( Node h1 , Node h2 ) { if ( h1 == null ) return h2 ; if ( h2 == null ) return h1 ; if ( h1 . data < h2 . data ) { h1 . next = merge ( h1 . next , h2 ) ; return h1 ; } else { h2 . next = merge ( h1 , h2 . next ) ; return h2 ; } } public static void Main ( String [ ] args ) { Node head1 = newNode ( 1 ) ; head1 . next = newNode ( 3 ) ; head1 . next . next = newNode ( 5 ) ; Node head2 = newNode ( 0 ) ; head2 . next = newNode ( 2 ) ; head2 . next . next = newNode ( 4 ) ; Node mergedhead = merge ( head1 , head2 ) ; printList ( mergedhead ) ; } }
Merge two sorted lists ( in | C # program to merge two sorted linked lists in - place . ; Linked List node ; Function to create newNode in a linkedlist ; A utility function to print linked list ; Merges two lists with headers as h1 and h2 . It assumes that h1 ' s ▁ data ▁ is ▁ smaller ▁ than ▁ ▁ or ▁ equal ▁ to ▁ h2' s data . ; if only one node in first list simply point its head to second list ; Initialize current and next pointers of both lists ; if curr2 lies in between curr1 and next1 then do curr1 -> curr2 -> next1 ; now let curr1 and curr2 to point to their immediate next pointers ; if more nodes in first list ; else point the last node of first list to the remaining nodes of second list ; Merges two given lists in - place . This function mainly compares head nodes and calls mergeUtil ( ) ; start with the linked list whose head data is the least ; Driver code ; 1 -> 3 -> 5 LinkedList created ; 0 -> 2 -> 4 LinkedList created
using System ; class GfG { public class Node { public int data ; public Node next ; } static Node newNode ( int key ) { Node temp = new Node ( ) ; temp . data = key ; temp . next = null ; return temp ; } static void printList ( Node node ) { while ( node != null ) { Console . Write ( node . data + " ▁ " ) ; node = node . next ; } } static Node mergeUtil ( Node h1 , Node h2 ) { if ( h1 . next == null ) { h1 . next = h2 ; return h1 ; } Node curr1 = h1 , next1 = h1 . next ; Node curr2 = h2 , next2 = h2 . next ; while ( next1 != null && curr2 != null ) { if ( ( curr2 . data ) >= ( curr1 . data ) & & ( curr2 . data ) <= ( next1 . data ) ) { next2 = curr2 . next ; curr1 . next = curr2 ; curr2 . next = next1 ; curr1 = curr2 ; curr2 = next2 ; } else { if ( next1 . next != null ) { next1 = next1 . next ; curr1 = curr1 . next ; } else { next1 . next = curr2 ; return h1 ; } } } return h1 ; } static Node merge ( Node h1 , Node h2 ) { if ( h1 == null ) return h2 ; if ( h2 == null ) return h1 ; if ( h1 . data < h2 . data ) return mergeUtil ( h1 , h2 ) ; else return mergeUtil ( h2 , h1 ) ; } public static void Main ( String [ ] args ) { Node head1 = newNode ( 1 ) ; head1 . next = newNode ( 3 ) ; head1 . next . next = newNode ( 5 ) ; Node head2 = newNode ( 0 ) ; head2 . next = newNode ( 2 ) ; head2 . next . next = newNode ( 4 ) ; Node mergedhead = merge ( head1 , head2 ) ; printList ( mergedhead ) ; } }
Recursive selection sort for singly linked list | Swapping node links | C # implementation of recursive selection sort for singly linked list | Swapping node links ; A Linked list node ; function to swap nodes ' currX ' and ' currY ' in a linked list without swapping data ; make ' currY ' as new head ; adjust links ; Swap next pointers ; function to sort the linked list using recursive selection sort technique ; if there is only a single node ; ' min ' - pointer to store the node having minimum data value ; ' beforeMin ' - pointer to store node previous to ' min ' node ; traverse the list till the last node ; if true , then update ' min ' and ' beforeMin ' ; if ' min ' and ' head ' are not same , swap the head node with the ' min ' node ; recursively sort the remaining list ; function to sort the given linked list ; if list is empty ; sort the list using recursive selection sort technique ; function to insert a node at the beginning of the linked list ; allocate node ; put in the data ; link the old list to the new node ; move the head to point to the new node ; function to print the linked list ; Driver code ; create linked list 10 -> 12 -> 8 -> 4 -> 6 ; sort the linked list
using System ; public class GFG { public class Node { public int data ; public Node next ; } ; static Node swapNodes ( Node head_ref , Node currX , Node currY , Node prevY ) { head_ref = currY ; prevY . next = currX ; Node temp = currY . next ; currY . next = currX . next ; currX . next = temp ; return head_ref ; } static Node recurSelectionSort ( Node head ) { if ( head . next == null ) return head ; Node min = head ; Node beforeMin = null ; Node ptr ; for ( ptr = head ; ptr . next != null ; ptr = ptr . next ) { if ( ptr . next . data < min . data ) { min = ptr . next ; beforeMin = ptr ; } } if ( min != head ) head = swapNodes ( head , head , min , beforeMin ) ; head . next = recurSelectionSort ( head . next ) ; return head ; } static Node sort ( Node head_ref ) { if ( ( head_ref ) == null ) return null ; head_ref = recurSelectionSort ( head_ref ) ; return head_ref ; } static Node push ( Node head_ref , int new_data ) { Node new_node = new Node ( ) ; new_node . data = new_data ; new_node . next = ( head_ref ) ; ( head_ref ) = new_node ; return head_ref ; } static void printList ( Node head ) { while ( head != null ) { Console . Write ( head . data + " ▁ " ) ; head = head . next ; } } public static void Main ( String [ ] args ) { Node head = null ; head = push ( head , 6 ) ; head = push ( head , 4 ) ; head = push ( head , 8 ) ; head = push ( head , 12 ) ; head = push ( head , 10 ) ; Console . WriteLine ( " Linked ▁ list ▁ before ▁ sorting : " ) ; printList ( head ) ; head = sort ( head ) ; Console . Write ( " sorting : " printList ( head ) ; } }
Insert a node after the n | C # implementation to insert a node after the n - th node from the end ; structure of a node ; function to get a new node ; allocate memory for the node ; put in the data ; function to insert a node after the nth node from the end ; if list is empty ; get a new node for the value ' x ' ; find length of the list , i . e , the number of nodes in the list ; traverse up to the nth node from the end ; insert the ' newNode ' by making the necessary adjustment in the links ; function to print the list ; Driver code ; Creating list 1 -> 3 -> 4 -> 5
using System ; class GfG { public class Node { public int data ; public Node next ; } static Node getNode ( int data ) { Node newNode = new Node ( ) ; newNode . data = data ; newNode . next = null ; return newNode ; } static void insertAfterNthNode ( Node head , int n , int x ) { if ( head == null ) return ; Node newNode = getNode ( x ) ; Node ptr = head ; int len = 0 , i ; while ( ptr != null ) { len ++ ; ptr = ptr . next ; } ptr = head ; for ( i = 1 ; i <= ( len - n ) ; i ++ ) ptr = ptr . next ; newNode . next = ptr . next ; ptr . next = newNode ; } static void printList ( Node head ) { while ( head != null ) { Console . Write ( head . data + " ▁ " ) ; head = head . next ; } } public static void Main ( String [ ] args ) { Node head = getNode ( 1 ) ; head . next = getNode ( 3 ) ; head . next . next = getNode ( 4 ) ; head . next . next . next = getNode ( 5 ) ; int n = 4 , x = 2 ; Console . Write ( " Original ▁ Linked ▁ List : ▁ " ) ; printList ( head ) ; insertAfterNthNode ( head , n , x ) ; Console . WriteLine ( ) ; Console . Write ( " Linked ▁ List ▁ After ▁ Insertion : ▁ " ) ; printList ( head ) ; } }
Insert a node after the n | C # implementation to insert a node after the nth node from the end ; structure of a node ; function to get a new node ; allocate memory for the node ; put in the data ; function to insert a node after the nth node from the end ; if list is empty ; get a new node for the value ' x ' ; Initializing the slow and fast pointers ; move ' fast _ ptr ' to point to the nth node from the beginning ; iterate until ' fast _ ptr ' points to the last node ; move both the pointers to the respective next nodes ; insert the ' newNode ' by making the necessary adjustment in the links ; function to print the list ; Driver code ; Creating list 1 -> 3 -> 4 -> 5
using System ; class GfG { public class Node { public int data ; public Node next ; } static Node getNode ( int data ) { Node newNode = new Node ( ) ; newNode . data = data ; newNode . next = null ; return newNode ; } static void insertAfterNthNode ( Node head , int n , int x ) { if ( head == null ) return ; Node newNode = getNode ( x ) ; Node slow_ptr = head ; Node fast_ptr = head ; for ( int i = 1 ; i <= n - 1 ; i ++ ) fast_ptr = fast_ptr . next ; while ( fast_ptr . next != null ) { slow_ptr = slow_ptr . next ; fast_ptr = fast_ptr . next ; } newNode . next = slow_ptr . next ; slow_ptr . next = newNode ; } static void printList ( Node head ) { while ( head != null ) { Console . Write ( head . data + " ▁ " ) ; head = head . next ; } } public static void Main ( ) { Node head = getNode ( 1 ) ; head . next = getNode ( 3 ) ; head . next . next = getNode ( 4 ) ; head . next . next . next = getNode ( 5 ) ; int n = 4 , x = 2 ; Console . WriteLine ( " Original ▁ Linked ▁ List : ▁ " ) ; printList ( head ) ; insertAfterNthNode ( head , n , x ) ; Console . WriteLine ( ) ; Console . WriteLine ( " Linked ▁ List ▁ After ▁ Insertion : ▁ " ) ; printList ( head ) ; } }
Make middle node head in a linked list | C # program to make middle node as head of Linked list ; Link list node ; Function to get the middle and set at beginning of the linked list ; To traverse list nodes one by one ; To traverse list nodes by skipping one . ; To keep track of previous of middle ; for previous node of middle node ; move one node each time ; move two node each time ; set middle node at head ; To insert a node at the beginning of linked list . ; allocate node ; link the old list off the new node ; move the head to point to the new node ; A function to print a given linked list ; Driver code ; Create a list of 5 nodes
using System ; public class GFG { class Node { public int data ; public Node next ; public Node ( int data ) { this . data = data ; next = null ; } } static Node head ; static void setMiddleHead ( ) { if ( head == null ) return ; Node one_node = head ; Node two_node = head ; Node prev = null ; while ( two_node != null && two_node . next != null ) { prev = one_node ; two_node = two_node . next . next ; one_node = one_node . next ; } prev . next = prev . next . next ; one_node . next = head ; head = one_node ; } static void push ( int new_data ) { Node new_node = new Node ( new_data ) ; new_node . next = head ; head = new_node ; } static void printList ( Node ptr ) { while ( ptr != null ) { Console . Write ( ptr . data + " ▁ " ) ; ptr = ptr . next ; } Console . WriteLine ( ) ; } public static void Main ( String [ ] args ) { head = null ; int i ; for ( i = 5 ; i > 0 ; i -- ) push ( i ) ; Console . Write ( " ▁ list ▁ before : ▁ " ) ; printList ( head ) ; setMiddleHead ( ) ; Console . Write ( " ▁ list ▁ After : ▁ " ) ; printList ( head ) ; } }
Sorted merge of two sorted doubly circular linked lists | C # implementation for Sorted merge of two sorted doubly circular linked list ; A utility function to insert a new node at the beginning of doubly circular linked list ; allocate space ; put in the data ; if list is empty ; pointer points to last Node ; setting up previous and next of new node ; update next and previous pointers of head_ref and last . ; update head_ref pointer ; function for Sorted merge of two sorted doubly linked list ; If first list is empty ; If second list is empty ; Pick the smaller value and adjust the links ; function for Sorted merge of two sorted doubly circular linked list ; if 1 st list is empty ; if 2 nd list is empty ; get pointer to the node which will be the last node of the final list ; store null to the ' next ' link of the last nodes of the two lists ; sorted merge of head1 and head2 ; ' prev ' of 1 st node pointing the last node ' next ' of last node pointing to 1 st node ; function to print the list ; Driver code ; list 1 : ; list 2 :
using System ; class GFG { public class Node { public int data ; public Node next , prev ; } ; static Node insert ( Node head_ref , int data ) { Node new_node = new Node ( ) ; new_node . data = data ; if ( head_ref == null ) { new_node . next = new_node ; new_node . prev = new_node ; } else { Node last = ( head_ref ) . prev ; new_node . next = head_ref ; new_node . prev = last ; last . next = ( head_ref ) . prev = new_node ; } head_ref = new_node ; return head_ref ; } static Node merge ( Node first , Node second ) { if ( first == null ) return second ; if ( second == null ) return first ; if ( first . data < second . data ) { first . next = merge ( first . next , second ) ; first . next . prev = first ; first . prev = null ; return first ; } else { second . next = merge ( first , second . next ) ; second . next . prev = second ; second . prev = null ; return second ; } } static Node mergeUtil ( Node head1 , Node head2 ) { if ( head1 == null ) return head2 ; if ( head2 == null ) return head1 ; Node last_node ; if ( head1 . prev . data < head2 . prev . data ) last_node = head2 . prev ; else last_node = head1 . prev ; head1 . prev . next = head2 . prev . next = null ; Node finalHead = merge ( head1 , head2 ) ; finalHead . prev = last_node ; last_node . next = finalHead ; return finalHead ; } static void printList ( Node head ) { Node temp = head ; while ( temp . next != head ) { Console . Write ( temp . data + " ▁ " ) ; temp = temp . next ; } Console . Write ( temp . data + " ▁ " ) ; } public static void Main ( ) { Node head1 = null , head2 = null ; head1 = insert ( head1 , 8 ) ; head1 = insert ( head1 , 5 ) ; head1 = insert ( head1 , 3 ) ; head1 = insert ( head1 , 1 ) ; head2 = insert ( head2 , 11 ) ; head2 = insert ( head2 , 9 ) ; head2 = insert ( head2 , 7 ) ; head2 = insert ( head2 , 2 ) ; Node newHead = mergeUtil ( head1 , head2 ) ; Console . Write ( " Final ▁ Sorted ▁ List : ▁ " ) ; printList ( newHead ) ; } }
Reverse a Doubly Linked List | Set 4 ( Swapping Data ) | C # Program to Reverse a List using Data Swapping ; Insert a new node at the head of the list ; Function to reverse the list ; Traverse the list and set right pointer to end of list ; Swap data of left and right pointer and move them towards each other until they meet or cross each other ; Swap data of left and right pointer ; Advance left pointer ; Advance right pointer ; Driver code
using System ; class GFG { public class Node { public int data ; public Node prev , next ; } ; static Node newNode ( int val ) { Node temp = new Node ( ) ; temp . data = val ; temp . prev = temp . next = null ; return temp ; } static void printList ( Node head ) { while ( head . next != null ) { Console . Write ( head . data + " ▁ < - > ▁ " ) ; head = head . next ; } Console . WriteLine ( head . data ) ; } static Node insert ( Node head , int val ) { Node temp = newNode ( val ) ; temp . next = head ; ( head ) . prev = temp ; ( head ) = temp ; return head ; } static Node reverseList ( Node head ) { Node left = head , right = head ; while ( right . next != null ) right = right . next ; while ( left != right && left . prev != right ) { int t = left . data ; left . data = right . data ; right . data = t ; left = left . next ; right = right . prev ; } return head ; } public static void Main ( String [ ] args ) { Node head = newNode ( 5 ) ; head = insert ( head , 4 ) ; head = insert ( head , 3 ) ; head = insert ( head , 2 ) ; head = insert ( head , 1 ) ; printList ( head ) ; Console . WriteLine ( " List ▁ After ▁ Reversing " ) ; head = reverseList ( head ) ; printList ( head ) ; } }
Check if a doubly linked list of characters is palindrome or not | C # program to check if doubly linked list is palindrome or not ; Structure of node ; Given a reference ( pointer to pointer ) to the head of a list and an int , inserts a new node on the front of the list . ; Function to check if list is palindrome or not ; Find rightmost node ; Driver program
using System ; class GFG { public class Node { public char data ; public Node next ; public Node prev ; } ; static Node push ( Node head_ref , char new_data ) { Node new_node = new Node ( ) ; new_node . data = new_data ; new_node . next = head_ref ; new_node . prev = null ; if ( head_ref != null ) head_ref . prev = new_node ; head_ref = new_node ; return head_ref ; } static bool isPalindrome ( Node left ) { if ( left == null ) return true ; Node right = left ; while ( right . next != null ) right = right . next ; while ( left != right ) { if ( left . data != right . data ) return false ; left = left . next ; right = right . prev ; } return true ; } public static void Main ( String [ ] args ) { Node head = null ; head = push ( head , ' l ' ) ; head = push ( head , ' e ' ) ; head = push ( head , ' v ' ) ; head = push ( head , ' e ' ) ; head = push ( head , ' l ' ) ; if ( isPalindrome ( head ) ) Console . Write ( " It ▁ is ▁ Palindrome " ) ; else Console . Write ( " Not ▁ Palindrome " ) ; } }
Print nodes between two given level numbers of a binary tree | c # program to print Nodes level by level between given two levels ; A binary tree Node has key , pointer to left and right children ; Given a binary tree , print nodes from level number ' low ' to level number ' high ' ; Marker node to indicate end of level ; Initialize level number ; Enqueue the only first level node and marker node for end of level ; Simple level order traversal loop ; Remove the front item from queue ; Check if end of level is reached ; print a new line and increment level number ; Check if marker node was last node in queue or level number is beyond the given upper limit ; Enqueue the marker for end of next level ; If this is marker , then we don 't need print it  and enqueue its children ; If level is equal to or greater than given lower level , print it ; Enqueue children of non - marker node ; Driver program to test for above functions
using System ; using System . Collections . Generic ; public class Node { public int data ; public Node left , right ; public Node ( int item ) { data = item ; left = right = null ; } } public class BinaryTree { public Node root ; public virtual void printLevels ( Node node , int low , int high ) { LinkedList < Node > Q = new LinkedList < Node > ( ) ; Node marker = new Node ( 4 ) ; int level = 1 ; Q . AddLast ( node ) ; Q . AddLast ( marker ) ; while ( Q . Count > 0 ) { Node n = Q . First . Value ; Q . RemoveFirst ( ) ; if ( n == marker ) { Console . WriteLine ( " " ) ; level ++ ; if ( Q . Count == 0 level > high ) { break ; } Q . AddLast ( marker ) ; continue ; } if ( level >= low ) { Console . Write ( n . data + " ▁ " ) ; } if ( n . left != null ) { Q . AddLast ( n . left ) ; } if ( n . right != null ) { Q . AddLast ( n . right ) ; } } } public static void Main ( string [ ] args ) { BinaryTree tree = new BinaryTree ( ) ; tree . root = new Node ( 20 ) ; tree . root . left = new Node ( 8 ) ; tree . root . right = new Node ( 22 ) ; tree . root . left . left = new Node ( 4 ) ; tree . root . left . right = new Node ( 12 ) ; tree . root . left . right . left = new Node ( 10 ) ; tree . root . left . right . right = new Node ( 14 ) ; Console . Write ( " Level ▁ Order ▁ traversal ▁ between ▁ given ▁ two ▁ levels ▁ is ▁ " ) ; tree . printLevels ( tree . root , 2 , 3 ) ; } }