public class TestB {
public static void permutation(String str,Set set){
if(str==null) return;
int len=str.length();
if(len==0 || len==1)return;
permutation(str.toCharArray(), 0,set);
}
private static void permutation(char[] str, int i, Set set) {
if (i >= str.length)
return;
if (i == str.length - 1) {
// System.out.println(String.valueOf(str));
set.add(String.valueOf(str));
} else {
for (int j = i; j < str.length; j++) {
char temp = str[j];
str[j] = str[i];
str[i] = temp;
permutation(str, i + 1,set);
temp = str[j];
str[j] = str[i];
str[i] = temp;
}
}
}
public static void main(String[] args) {
Set<String>set=new HashSet<>();
permutation("acda",set);
for(String s:set){
System.out.println(s);
}
}
}
