LeetCode 1941. Check if All Characters Have Equal Number of Occurrences

class Solution {
public:
    bool areOccurrencesEqual(string s) {
        int c[26] = {0};
        for (char ch : s) ++c[ch - 'a'];
        int m = 0;
        for (int x : c)
            if (x) {
                m = max(m, x);
                if (m != x) return false;
            }
        return true;
    }
};