Largest number less than or equal to N in BST ( Iterative Approach ) | Java code to find the largest value smaller than or equal to N ; To create new BST Node ; To insert a new node in BST ; if tree is empty return new node ; if key is less then or greater then node value then recur down the tree ; return the ( unchanged ) node pointer ; Returns largest value smaller than or equal to key . If key is smaller than the smallest , it returns - 1. ; Driver code
class GFG { static class Node { int key ; Node left , right ; } ; static Node newNode ( int item ) { Node temp = new Node ( ) ; temp . key = item ; temp . left = temp . right = null ; return temp ; } static Node insert ( Node node , int key ) { if ( node == null ) return newNode ( key ) ; if ( key < node . key ) node . left = insert ( node . left , key ) ; else if ( key > node . key ) node . right = insert ( node . right , key ) ; return node ; } static int findFloor ( Node root , int key ) { Node curr = root , ans = null ; while ( curr != null ) { if ( curr . key <= key ) { ans = curr ; curr = curr . right ; } else curr = curr . left ; } if ( ans != null ) return ans . key ; return - 1 ; } public static void main ( String [ ] args ) { int N = 25 ; Node root = new Node ( ) ; insert ( root , 19 ) ; insert ( root , 2 ) ; insert ( root , 1 ) ; insert ( root , 3 ) ; insert ( root , 12 ) ; insert ( root , 9 ) ; insert ( root , 21 ) ; insert ( root , 19 ) ; insert ( root , 25 ) ; System . out . printf ( " % d " , findFloor ( root , N ) ) ; } }