hardDynamic ProgrammingMath 0 views

Count Special Integers

We call a positive integer special if all of its digits are distinct.

We call a positive integer special if all of its digits are distinct.

Given a positive integer n, return the number of special integers that belong to the interval [1, n].

Example 1

Input: n = 20

Output: 19

Explanation: All the integers from 1 to 20, except 11, are special. Thus, there are 19 special integers.

Example 2

Input: n = 5

Output: 5

Explanation: All the integers from 1 to 5 are special.

Example 3

Input: n = 135

Output: 110

Explanation: There are 110 integers from 1 to 135 that are special. Some of the integers that are not special are: 22, 114, and 131.

Constraints

  • 1 <= n <= 2 * 10^9

Hints

Companies

No companies reported yet.

Discussion

Sign in to join the discussion.

Loading discussion...

Test results

No test cases yet.