import java.util.Arrays;


public class StringOps
{

	/**
	 * precondition: s1 and s2 cannot be null
	 * @param s1 string 1
	 * @param s2 string 2
	 * @return true if s1 & s2 are anagrams – false otherwise
	 */
	public static boolean AreAnagrams(String s1, String s2)
	{
		if (s1 == null || s2 == null)
			throw new IllegalArgumentException ("null string");

		if (s1.length() != s2.length())
			return false;

		String one;
		String two;
		char[] three;
		char[] four;

		one = s1;
		two = s2;

		one = one.toLowerCase();
		two = two.toLowerCase();

		three = one.toCharArray();
		four = two.toCharArray();
		Arrays.sort(three);
		Arrays.sort(four);
		boolean num = false;

		if (three.length != four.length)
			return false;
		if (s1 == s2)
			return true;

		for(int i = 0; i < three.length; i++)
			if (three[i] == four[i])
					num = true;

		return num;
	}

	/**
	 * precondition: s1 and s2 cannot be null
	 * @param s1 string 1
	 * @param s2 string 2
	 * @return return true if s1 is a substring of s2 – false otherwise
	 */
	public static boolean isSubstring(String s1, String s2)
	{
		if (s1 == null || s2 == null)
			throw new IllegalArgumentException ("null string");
		int count = 0;
		boolean nums = true;

		if (s1.length() == s2.length())
			return true;

		if (s1.length() < s2.length())

			for(int i = 0; i < s2.length()- s1.length() || nums; i++)
			{
				System.out.print(s2.substring(i,i+s1.length()));
				System.out.println(s1.length());
				if(s2.substring(i,i+s1.length()).equals(s1))
					nums = true;

			}
		else
			return false;



		return nums;
	}

}