## Lucy and Flowers | HackerRank Solution [Medium]

The number of possible Binary Search Trees with n keys is Catalan Number (Cn). You could learn about Catalan Number & Binomial Coefficient.

## Program for Nth Catalan Number

Catalan numbers (Cn) are a sequence of natural numbers. Nth Catalan number has applications in many counting problems.

## How to calculate Binomial Coefficient (nCr) in O(r) time complexity

The recomputations in calculating binomial coefficient (nCr) can be avoided by exploiting optimal substructure and overlapping subproblems

## Sherlock and MiniMax | HackerRank Solution [Hard]

Given an integer range, for all M in that inclusive range, determine the minimum – abs(arr[i]-M) for all i

## nCr table | HackerRank Solution [Medium]

Jim is doing his discrete maths homework which requires him to repeatedly calculate nCr(n choose r) for different values of n

## Counting Bits O(n) Solution – LeetCode [Easy] | Brian Kernighan’s Algorithm

Given an integer n, return an array ans of length n + 1 such that for each i (0 <= i <= n), ans[i] is the number of 1's in the binary representation of i.

## Palindrome Solution | CodeChef [Easy]

A simple recursive method to generate a numeric palindrome from any number is to reverse its digits and add it to the original. If the sum is not a palindrome (which means, it is not the same number from left to right and right to left), repeat this procedure.

## Anagram Problem [Hard]

Alansh has several words. For each given word, he wants to find the number of palindromic anagrams of that word.

## Modular Multiplicative Inverse and Modular Combinatorics (nCr % prime) in C++

In mathematics, particularly in the area of arithmetic, a modular multiplicative inverse of an integer a is an integer x such that the product ax is congruent to 1 with respect to the modulus m.

## Arranging Cupcakes Solution

On the day of the party, the Chef was over-seeing all the food arrangements as well, ensuring that every item was in its designated position. The host was satisfied with everything except the cupcakes. He noticed they were arranged neatly in the shape of a rectangle. He asks the Chef to make it as square-like as possible.