Software Developer

Given a string 'S' of length 'L', return the length of the longest substring without repeating characters.

Example:

Suppose given input is "abacb", then the length of the longest substring without repeating characters will be 3 ("acb").

You are given a string 'str' of lowercase alphabets and an integer 'k' .

Your task is to return the count all the possible substrings that have exactly 'k' distinct characters.

For example:

'str' = abcad and 'k' = 2. 

We can see that the substrings {ab, bc, ca, ad} are the only substrings with 2 distinct characters. 

Therefore, the answer will be 4.    

You are given the head node of a singly linked list 'head'. Your task is to modify the linked list in such a way that all the even valued nodes appear before the all odd valued node and order of nodes remain the same.

Example :-

The given singly linked list is  6 -> 5 -> 3 -> 4 -> 7 -> 1 -> 2 

The modified linked list should have all even values in starting and odd values in the end.