Qbasic code to solve for the permutation of a given number

问题

Write a QBASIC to Solve find the permutation of a given numbers. I've tried this in a Qbasic compiler

Input n
Input r
P = n! / (n - r)!
Print p

来源：https://stackoverflow.com/questions/60148215/qbasic-code-to-solve-for-the-permutation-of-a-given-number