Challenge problem

#1

can anyone tell me why it is showing compilation error?

import java.util.*;

public class Main {

public static void main(String args[]) {
   Scanner scn = new Scanner(System.in);
	String str = scn.next();
	ArrayList<String> list = getP(str);
	Collections.sort(list);
	for (int i = 0; i < list.size(); i++) {
		if (list.get(i).compareTo(str) < 0) {
			System.out.println(list.get(i));
		}
	}
}
public static ArrayList<String> getP(String str) {
	if (str.length() == 0) {
		ArrayList<String> base = new ArrayList();
		base.add("");
		return base;
	}
	char cc = str.charAt(0);
	String ros = str.substring(1);
	ArrayList<String> myResult = new ArrayList();
	ArrayList<String> recResult = getP(ros);
	for (String s : recResult) {
		// StringBuilder sb=new StringBuilder(s);
		for (int j = 0; j <= s.length(); j++) {
			// sb.insert(j, cc);
			String val = s.substring(0, j) + cc + s.substring(j);
			myResult.add(val);
		}
	}
	return myResult;
}

}

#2

Hey @VinayakSingh11111
code is fine just a change
In a base Case
ArrayList base = new ArrayList<>(); instead of ArrayList base = new ArrayList();
and also a small change
ArrayList myResult = new ArrayList<>(); instead of ArrayList myResult = new ArrayList();
correct code :
import java.util.*;

public class Main {
public static void main(String args[]) {
Scanner scn = new Scanner(System.in);
String str = scn.next();
ArrayList list = getP(str);
Collections.sort(list);
for (int i = 0; i < list.size(); i++) {
if (list.get(i).compareTo(str) < 0) {
System.out.println(list.get(i));
}
}
}

public static ArrayList<String> getP(String str) {
	if (str.length() == 0) {
		ArrayList<String> base = new ArrayList<>();
		base.add("");
		return base;
	}
	char cc = str.charAt(0);
	String ros = str.substring(1);
	ArrayList<String> myResult = new ArrayList<>();
	ArrayList<String> recResult = getP(ros);
	for (String s : recResult) {
		// StringBuilder sb=new StringBuilder(s);
		for (int j = 0; j <= s.length(); j++) {
			// sb.insert(j, cc);
			String val = s.substring(0, j) + cc + s.substring(j);
			myResult.add(val);
		}
	}
	return myResult;
}

}