I had 4 coding questions:-

1. https://leetcode.com/problems/subtract-the-product-and-sum-of-digits-of-an-integer/

2. String manipulation- List of letters is given = list=['a','b','c','d']. Count the number of words whose all the letters are found in list.
   For e.g :- String s = "Hello, this is Batman" and list = [ e, i ,h, l, o, s] so output is 2
   h,e,l,l,o ----- all letters are found in list.
   t,h,i,s ------ t is not found in list
   i,s ----- all letters found in list
   B,a,t,m,a,n- not all letters found in list.

3. String manipulation:- Simulate working process of text editior i.e UNDO,PASTE,COPY,DELETE,INSERT

4. Given an array of positive integers, detect cyclc pairs of numbers.
   For e.g:- a = [13,5604,31,13,4560,546,654,456] output is 5