You are given a string ‘STR’ of lowercase alphabets and an integer K. Your task is to count all the possible substrings that are not necessarily distinct but should have exactly K distinct chara...

Ninja is learning the binary representation of the numbers. He wanted to practice the topic, so he picked...

Ninja wants to build a triangle pattern for English alphabets for a given integer input.

Example, for ‘N’ = 4

Pattern:

ABCDDCBA
 ABCCBA
  ABBA
   AA

You are given a string ‘S’ of length ‘N’ which consists of digits from 0 to 9 only. If the mapping of characters from a to z is like a = 1, b = 2, c = ...

Given two strings, ‘A’ and ‘B’. Return the shortest supersequence string ‘S’, containing both ‘A’ and ‘B’ as its subsequences. If there are multiple answers, return any of them.

Ninja got holiday homework from his English teacher. His teacher gave him a string and told him to find the rank of the string if the string is sorted in lexicographical order.