easyArrayEnumerationHash TableRecursion 0 views

Unique 3-Digit Even Numbers

You are given an array of digits called digits.

You are given an array of digits called digits. Your task is to determine the number of distinct three-digit even numbers that can be formed using these digits.

Note: Each copy of a digit can only be used once per number, and there may not be leading zeros.

Unique 3-Digit Even Numbers diagram

Example 1

Input: digits = [1,2,3,4]

Output: 12

Explanation: The 12 distinct 3-digit even numbers that can be formed are 124, 132, 134, 142, 214, 234, 312, 314, 324, 342, 412, and 432. Note that 222 cannot be formed because there is only 1 copy of the digit 2.

Example 2

Input: digits = [0,2,2]

Output: 2

Explanation: The only 3-digit even numbers that can be formed are 202 and 220. Note that the digit 2 can be used twice because it appears twice in the array.

Example 3

Input: digits = [6,6,6]

Output: 1

Explanation: Only 666 can be formed.

Example 4

Input: digits = [1,3,5]

Output: 0

Explanation: No even 3-digit numbers can be formed.

Constraints

  • 3 <= digits.length <= 10
  • 0 <= digits[i] <= 9

Hints

Companies

No companies reported yet.

Discussion

Sign in to join the discussion.

Loading discussion...

Test results

No test cases yet.