This time no story, no theory

Accumul.java

// Accumul.accum("abcd");    // "A-Bb-Ccc-Dddd"
// Accumul.accum("RqaEzty"); // "R-Qq-Aaa-Eeee-Zzzzz-Tttttt-Yyyyyyy"
// Accumul.accum("cwAt");    // "C-Ww-Aaa-Tttt"
public class Accumul {
  public String accum(String s) {
    StringBuilder result = new StringBuilder();
    int i = 0;
    for (char c : s.toCharArray()) {
      if (i > 0)
        result.append('-');
      result.append(Character.toUpperCase(c));
      for (int j = 0; j < i; j++)
        result.append(Character.toLowerCase(c));
      i++;
    }
    return result.toString();
  }
}