We have a binary search tree and a number N. Our task is to find the greatest number in the binary search tree that is less than or equal to N. Print the value of the element if it exists otherwise print -1.
Examples: For the above given binary search tree-
Input : N = 24 Output :result = 21 (searching for 24 will be like-5->12->21) Input : N = 4 Output : result = 3 (searching for 4 will be like-5->2->3)
We have discussed recursive approach in below post.
Largest number in BST which is less than or equal to N
Here an iterative approach is discussed. We try to find the predecessor of the target. Keep two pointers, one pointing to the current node and one for storing the answer. If the current node’s data > N, we move towards left. In other case, when current node’s data is less than N, the current node can be our answer (so far), and we move towards right.
Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.
- Largest number in BST which is less than or equal to N
- Inorder predecessor and successor for a given key in BST | Iterative Approach
- K'th Largest Element in BST when modification to BST is not allowed
- Largest subset having with sum less than equal to sum of respective indices
- Smallest number in BST which is greater than or equal to N
- Count the number of unordered triplets with elements in increasing order and product less than or equal to integer X
- Pair with largest sum which is less than K in the array
- Find largest factor of N such that N/F is less than K
- Check if a Binary Tree is BST : Simple and Efficient Approach
- Queries for greater than and not less than
- Sum of all array elements less than X and greater than Y for Q queries
- Two nodes of a BST are swapped, correct the BST | Set-2
- Find k-th smallest element in BST (Order Statistics in BST)
- Convert a normal BST to Balanced BST
- Two nodes of a BST are swapped, correct the BST
- For each element in 1st array count elements less than or equal to it in 2nd array
- Find all possible subarrays having product less than or equal to K
- Maximum sum subarray having sum less than or equal to given sum using Set
- Number of elements smaller than root using preorder traversal of a BST
- Length of longest subarray in which elements greater than K are more than elements not greater than K
If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to email@example.com. See your article appearing on the GeeksforGeeks main page and help other Geeks.
Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.