1399_count_largest_group.md

Count Largest Group

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.

Solution

class Solution:
    def countLargestGroup(self, n: int) -> int:
        def sum_digits(num):
            return sum([int(d) for d in str(num)])
        dic = {}

        for i in range(1, n + 1):
            s = sum_digits(i)

            if s in dic:
                dic[s] += [s]
            else:
                dic[s] = [s]

        length = [len(value) for value in dic.values()]
        return length.count(max(length))