Calculate How Many Numbers with Unique Digits

Published by persolut in
loopsmathnumbers

The function is given an integer num. Count the numbers with unique digits in the range 0 <= num < 10^num.

Examples

numsWithUniqueDigits(2) ➞ 91
// There are 100 numbers in total (from 0 to 99 inclusive).
// The following 9 numbers should not be counted:
// 11, 22, 33, 44, 55, 66, 77, 88, 99
// Thus 100 – 9 ➞ 91

Notes

N/A

Watch a quick demo on how Edabit works.