/**
* Created by stms130834 on 2014/4/28.
*/
public class TheLuckyString {
public static void main(String[] args) {
TheLuckyString t = new TheLuckyString();
//nhhhhhalrn
//zzddvveett 39480
System.out.println(t.count("aabbbaa"));
}
public int count(String s) {
int[] letters = new int[26];
for (int i = 0; i < s.length(); i++) {
letters[s.charAt(i) - 'a']++;
}
int total = 0;
for(int i=0;i<letters.length;i++){
if(letters[i] > 0 ) {
String prefix = ""+(char)('a'+i);
int[] newLetters = new int[26];
System.arraycopy(letters,0, newLetters, 0, 26);
newLetters[i]--;
int solutionsCount = findSolutionsCount(prefix, newLetters, s);
total+=solutionsCount;
}
}
return total;
}
private int findSolutionsCount(String prefix, int[] letters, String s) {
int total = 0;
if(s.length() == prefix.length()) {
System.out.println(prefix);
return 1;
}
for(int i=0;i<letters.length;i++){
char c = (char)('a'+i);
if(letters[i] > 0 && c != prefix.charAt(prefix.length()-1)) {
int[] newLetters = new int[26];
System.arraycopy(letters,0, newLetters, 0, 26);
newLetters[i]--;
prefix+=c;
int solutionsCount = findSolutionsCount(prefix, newLetters, s);
total+=solutionsCount;
}
}
return total;
}
}
