Given a binary tree, find out if it is a binary search tree or not.
You can traverse the tree in in-order way, and see if the elements are assending.
You may either put the elements into an array and see if the array is sorted in assending way,
or while traversing see if the current element is always greater than or equal to previous element.
return false is current data is less than previously printed data.
may use a static variable to hold the last printed value.
Complete solution can be found @ http://javajee.com/solution-checking-if-a-binary-tree-is-a-binary-search....
For a BST, all left nodes should be less than or equal to current node and current node must be less than all right nodes.
We will have a recursive function that checks if this property is true for root node and all its sub trees:
If the method get null node, it may return true, and should be first checked (exit condition for the recursion).
Check if all left nodes are less than or equal to current node and current node is less than all right nodes
Pass current minimum and current data to left subtree
Pass current data and current max to right sub trees
Complete solution can be found @ http://javajee.com/solution-check-if-a-binary-tree-is-a-binary-search-tr....
Here, I will giving some of the common approach(es) for the problems on trees and graph given earlier.
The solutions may not be the best. But it will surely give enough information to start thinking. Convert them into algorithms (or code) to gain best out of these.
Original list of questions can be found @ http://javajee.com/problems-list-of-problems-on-trees-and-graphs-for-int....