## Number of ways to arrange K different objects taking N objects at a time

Given two integers K and N, the task is to count the number of ways to arrange K different objects taking N objects at a… Read More »

## Count different numbers possible using all the digits their frequency times

Given an array arr[] which contains the frequency of the digits (0-9), the task is to find the count of numbers possible using each digit… Read More »

## Check if a given number divides the sum of the factorials of its digits

Given an integer N, the task is to check whether N divides the sum of the factorials of its digits. Examples: Input: N = 19… Read More »

## Check whether factorial of N is divisible by sum of first N natural numbers

Given a number ‘N’. Check whether factorial of ‘N’ is divisible by the sum of first ‘N’ natural numbers or not? If divisibility is possible,… Read More »

## Check if factorial of N is divisible by the sum of squares of first N natural numbers

Given an integer N, the task is to find whether fact(N) is divisible by sum(N) where fact(N) is the factorial of N and sum(N) =… Read More »

## Number of ways to go from one point to another in a grid

Given the NxN grid of horizontal and vertical roads. The task is to find out the number of ways that the person can go from… Read More »

## Find the smallest number X such that X! contains at least Y trailing zeros.

Given an integer Y, find the smallest number X such that X! contains at least Y trailing zeros. Prerequisites – Count trailing zeroes in factorial… Read More »

## Program to calculate the value of nPr

Given two numbers n and r, the task is to find the value of nPr. nPr represents n permutation r which is calculated as n!/(n-k)!.… Read More »

## Count numbers having N 0’s and and M 1’s with no leading zeros

Given two integer N and M, the task is to find the number of distinct numbers having N 0’s and M 1’s with no leading… Read More »

## Find GCD of factorial of elements of given array

Given an array with N positive integers. Find the GCD of factorials of all elements of array. Examples: Input : arr[] = {3, 4, 8,… Read More »

## Number of trailing zeroes in base B representation of N!

Given two positive integers B and N. The task is to find the number of trailing zeroes in b-ary (base B) representation of N! (factorial… Read More »

## Number of trailing zeroes in base 16 representation of N!

Given an integer N, the task is to find the number of trailing zeroes in the base 16 representation of the factorial of N. Examples:… Read More »

## Numbers of Length N having digits A and B and whose sum of digits contain only digits A and B

Given three positive integers N, A and B. The task is to count the numbers of length N containing only digits A and B and… Read More »

## Check if N is a Factorial Prime

Given a positive integer N, the task is to check if N is a Factorial prime or not. If it is a factorial prime then… Read More »

## Range and Update Sum Queries with Factorial

Given an array arr[] of N integers and number of queries Q. The task is to answer three types of queries. Update [l, r] –… Read More »