SWE Intern

You are given a string ‘STR’. You need to find and return the minimum number of characters to be deleted from ‘STR’ so that the frequency of each character in the string becomes unique.

Example:

If the given string is “aaBBccc” then the frequency of characters: { a:2, B:2, c:3 }. Now, as ‘a’ and ‘B’ both have the same frequency 2, we need to delete one character either one ‘a’ or one ‘B’, to make their frequency different. After deleting any character we will get frequency as 1,2 and 3, as they all are different. Thus we got our solution as 1.

Given a binary tree, convert this binary tree into its mirror tree.

A binary tree is a tree in which each parent node has at most two children.

Mirror of a Tree: Mirror of a Binary Tree T is another Binary Tree M(T) with left and right children of all non-leaf nodes interchanged.

Note:

1. Make in-place changes, that is, modify the nodes given a binary tree to get the required mirror tree.

You are given two Singly Linked Lists of integers, which may have an intersection point.

Your task is to return the first intersection node. If there is no intersection, return NULL.

Example:-

The Linked Lists, where a1, a2, c1, c2, c3 is the first linked list and b1, b2, b3, c1, c2, c3 is the second linked list, merging at node c1.

You are given a string 'S'. Your task is to check whether the string is palindrome or not. For checking palindrome, consider alphabets and numbers only and ignore the symbols and whitespaces.

Note :

String 'S' is NOT case sensitive.

Example :

Let S = “c1 O$d@eeD o1c”.
If we ignore the special characters, whitespaces and convert all uppercase letters to lowercase, we get S = “c1odeedo1c”, which is a palindrome. Hence, the given string is also a palindrome.