text: class Solution {
  public:
      bool areOccurrencesEqual(string s) {
          vector<int> charCount(26, 0);
          int common_count = 0;
          for(char& c : s) {
              int key = c - 'a';
              charCount[key]++;
              common_count = charCount[key];
          }
          for(int i = 0; i < 26; i++) {
              if(charCount[i] == 0)   
                  continue;
              if(charCount[i] != common_count)
                  return false;
          }
          return true;
      }
  };