[ASSIGNMENT] 🏆Challenge🏆=>Permutation calculator

Question

Create a permutation calculator i hope you know about permutation!
For those who don't know about permutation :
To calculate permutation we need two numbers say 'n' and 'r' and so create a code that calculate permutation of two number formula to calculate permutation is : n!/(n-r)! where n and r are entered by user

FORMULA: n!/(n-r)!

NOTE: In permutation value of n should be greater than r

EXAMPLE:

input: n:5 r:4

output: 5Pr: 120

Hope I am able to be clear thank you
🎉 HAPPY CODING!🎉

Answer 1

Hear is my submission for example

https://code.sololearn.com/cWf0gZIk1J20/?ref=app

Answer 2

//my try in java //see this , i am happy 😂
https://code.sololearn.com/cWuY8IrGWnDh/?ref=app

Answer 3

https://code.sololearn.com/c3J3lTf5idOm/?ref=app

Answer 4

Using ES6
https://code.sololearn.com/WKc203Z6qMM6/?ref=app

Answer 5

https://code.sololearn.com/cTpFkc3IKQir/?ref=app

Answer 6

https://code.sololearn.com/cUihXF8wBjsc/?ref=app

Answer 7

https://code.sololearn.com/c9JZYmHMDFx2/?ref=app

Answer 8

https://code.sololearn.com/cTBVUM7Tr8Ag/#java