Solved riddles or learned algorithms
Game of bots -> https://www.hackerearth.com/practice/data-structures/hash-tables/basics-of-hash-tables/practice-problems/algorithm/game-of-bots/
Palindromic sub string Length -> https://www.hackerearth.com/submission/26321814/
Next smaller number with the same digits -> https://www.codewars.com/kata/5659c6d896bc135c4c00021e
Sparse arrays -> https://www.hackerrank.com/challenges/sparse-arrays/problem