import java.util.ArrayList;
public class {
public static void main(String[] args) {
ArrayList<String> result = new ArrayList<>();
helper(result, "abc", new StringBuilder(), 0);
for (String s : result)
System.out.println(s);
}
private static void helper(ArrayList<String> result, String s, StringBuilder sb, int index) {
for (int i = index; i < s.length(); i++) {
sb.append(s.charAt(i));
result.add(sb.toString());
helper(result, s, sb, i + 1);
sb.deleteCharAt(sb.length() - 1);
}
}
}
近期评论