java.lang.Object
g3701_3800.s3704_count_no_zero_pairs_that_sum_to_n.Solution

public class Solution extends Object
3704 - Count No-Zero Pairs That Sum to N.

Hard

A no-zero integer is a positive integer that does not contain the digit 0 in its decimal representation.

Given an integer n, count the number of pairs (a, b) where:

  • a and b are no-zero integers.
  • a + b = n

Return an integer denoting the number of such pairs.

Example 1:

Input: n = 2

Output: 1

Explanation:

The only pair is (1, 1).

Example 2:

Input: n = 3

Output: 2

Explanation:

The pairs are (1, 2) and (2, 1).

Example 3:

Input: n = 11

Output: 8

Explanation:

The pairs are (2, 9), (3, 8), (4, 7), (5, 6), (6, 5), (7, 4), (8, 3), and (9, 2). Note that (1, 10) and (10, 1) do not satisfy the conditions because 10 contains 0 in its decimal representation.

Constraints:

  • 2 <= n <= 1015
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • countNoZeroPairs

      public long countNoZeroPairs(long n)