// 1399. Count Largest Group #include "leetcode.h" /* * 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. */ int get_num(int n) { int res = 0; while (n) { res += n % 10; n /= 10; } return res; } int countLargestGroup(int n) { int arr[37] = {0}, max = 0; for (int i = 1; i <= n; i++) { int curr = get_num(i); arr[curr]++; if (arr[curr] > max) max = arr[curr]; } int cnt = 0; for (int i = 1; i <= 36; i++) if (arr[i] == max) cnt++; return cnt; } int main() { printf("%d\n", countLargestGroup(13)); // expect: 4 printf("%d\n", countLargestGroup(2)); // expect: 2 }