public class StringHash {

    // This code computes the built-in hash function of the String
    // class (present as the hashCode method of the String class).
    // Computes a weighted sum of the individual letters of
    // the string (designed to evenly balance hash values among
    // different strings without biasing towards, e.g.,
    // particular or smaller values).
    public static int stringHashCode(String s) {
        char[] chars = s.toCharArray();
        int hash = 0;
        for (int i = 0; i < chars.length; i++) {
            hash = 31 * hash + chars[i];
        }
        return hash;
    }

    private static void test(String s) {
        System.out.println("\"" + s + "\" hash code is " + stringHashCode(s));
        System.out.println("\"" + s + "\" hash code (built-in) is " + s.hashCode());
    }

    public static void main(String[] args) {
        test("Bowdoin");
        test("College");
        test("the");
        test("");
        test("computer science is the best");
    }

}