SDE - 1

You have been given a binary tree consisting of ‘N’ nodes where nodes have distinct integer values. Your task is to convert the given Binary Tree to a Binary Search Tree(BST).

Note: The conversion must be done in such a way that keeps the original structure of the Binary Tree.

A binary search tree (BST) is a binary tree data structure which has the following properties.

• The left subtree of a node contains only nodes with data less than the node’s data.
• The right subtree of a node contains only nodes with data greater than the node’s data.
• Both the left and right subtrees must also be binary search trees. 

For Example:

For the given binary tree :

The BST will be:

Note: Each node is associated with a unique integer value.

You have been given an integer array/list(arr) and a number 'Sum'. Find and return the total number of pairs in the array/list which when added, results equal to the 'Sum'.

Note:

Given array/list can contain duplicate elements.

(arr[i],arr[j]) and (arr[j],arr[i]) are considered same.

For a given two strings, 'str1' and 'str2', check whether they are a permutation of each other or not.

Permutations of each other

Two strings are said to be a permutation of each other when either of the string's characters can be rearranged so that it becomes identical to the other one.

Example: 
str1= "sinrtg" 
str2 = "string"

The character of the first string(str1) can be rearranged to form str2 and hence we can say that the given strings are a permutation of each other.