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1399. Count Largest Group

Difficulty Topics

Description

You are given an integer n.

Each number from 1 to n is grouped according to the sum of its digits.

Return the number of groups that have the largest size.

 

Example 1:

Input: n = 13
Output: 4
Explanation: There are 9 groups in total, they are grouped according sum of its digits of numbers from 1 to 13:
[1,10], [2,11], [3,12], [4,13], [5], [6], [7], [8], [9].
There are 4 groups with largest size.

Example 2:

Input: n = 2
Output: 2
Explanation: There are 2 groups [1], [2] of size 1.

 

Constraints:

  • 1 <= n <= 104

Solution

count-largest-group.py
class Solution:
    def countLargestGroup(self, n: int) -> int:
        d = collections.defaultdict(int)
        for i in range(1, n + 1):
            t = sum(map(int, list(str(i))))
            d[t] += 1
        return sum(1 for i in d.values() if i >= max(d.values()))