Skip to content

2549. Count Distinct Numbers on Board

Difficulty Topics

Description

You are given a positive integer n, that is initially placed on a board. Every day, for 109 days, you perform the following procedure:

  • For each number x present on the board, find all numbers 1 <= i <= n such that x % i == 1.
  • Then, place those numbers on the board.

Return the number of distinct integers present on the board after 109 days have elapsed.

Note:

  • Once a number is placed on the board, it will remain on it until the end.
  • % stands for the modulo operation. For example, 14 % 3 is 2.

 

Example 1:

Input: n = 5
Output: 4
Explanation: Initially, 5 is present on the board. 
The next day, 2 and 4 will be added since 5 % 2 == 1 and 5 % 4 == 1. 
After that day, 3 will be added to the board because 4 % 3 == 1. 
At the end of a billion days, the distinct numbers on the board will be 2, 3, 4, and 5.

Example 2:

Input: n = 3
Output: 2
Explanation: 
Since 3 % 2 == 1, 2 will be added to the board. 
After a billion days, the only two distinct numbers on the board are 2 and 3.

 

Constraints:

  • 1 <= n <= 100

Solution

count-distinct-numbers-on-board.py
class Solution:
    def distinctIntegers(self, n: int) -> int:
        return 1 if n == 1 else n - 1