test1

Class Practice1A

java.lang.Object

test1.Practice1A

public class Practice1A
extends Object

Field Summary

Fields

Modifier and Type	Field and Description
static String	TEST_VERSION The string describing this test version.

Method Summary

Modifier and Type	Method and Description
static String	hello(String name) Returns the string "Hello, " followed by the given name.
static List<Character>	repeatedChars(String s) Returns a list of the characters that appear more than once in the string s.
static List<Character>	shuffle(List<Character> t) Returns a new list of characters formed by shuffling the characters of the given list.
static String	toString(List<Character> t) Returns the string formed by concatenating the characters contained in the given list.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

TEST_VERSION

public static final String TEST_VERSION

The string describing this test version.

See Also:

Constant Field Values

Method Detail

hello

public static String hello(String name)

Returns the string "Hello, " followed by the given name. For example:

 Practice1A.hello("Tanya Tagaq");
 

returns the string:

 "Hello, Tanya Tagaq"
 

Parameters:

name - a non-null string

Returns:

the string "Hello, " followed by the given name.

toString

public static String toString(List<Character> t)

Returns the string formed by concatenating the characters contained in the given list. The list is not modified by this method.

For example, if t was the list:

 ['g', 'o', 'o', 'd', 'b', 'y', 'e']
 

Then Practice1A.toString(t) would return the string:

 "goodbye"
 

Parameters:

t - a non-null list of characters

Returns:

the string formed by concatenating the characters in t

Throws:

IllegalArgumentException - if the list t is empty

shuffle

public static List<Character> shuffle(List<Character> t)

Returns a new list of characters formed by shuffling the characters of the given list. It is a precondition that the given list t contains at least two elements, and that the number of elements is an even number. The list is not modified by this method.

To shuffle the characters in t, imagine splitting the list t in half so that the first (n / 2) characters of t are in one sublist, and the remaining (n / 2) characters of t are in the second sublist. The new returned list is formed by adding the first character of the first sublist to the new list, then adding the first character of the second sublist, then adding the second character of the first sublist, then adding the second character of the second sublist, and so on, until all of the characters in the two sublists are added to the new list.

For example, if t was the list:

 ['a', 'b', 'c', 'd', 'e', 'f']
 

then splitting t into two sublists yields:

 ['a', 'b', 'c'] and ['d', 'e', 'f']
 

Take the first two characters of each sublist and add them to the new list:

 ['a', 'd']
 

Then take the next two characters of each sublist and add them to the new list:

 ['a', 'd', 'b', 'e']
 

Then take the next two characters of each sublist and add them to the new list:

 ['a', 'd', 'b', 'e', 'c', 'f']
 

Parameters:

t - a non-null list of characters

Returns:

a new list equal to the shuffle of the characters in t

Precondition:

t.size() is greater than or equal to 2 and t.size() is an even number

repeatedChars

public static List<Character> repeatedChars(String s)

Returns a list of the characters that appear more than once in the string s. The returned list contains no duplicate characters. For example:

 Practice1A.repeatedChars("hi")        returns the empty list
 Practice1A.repeatedChars("EECS")      returns the list ['E']
 Practice1A.repeatedChars("EECS2030")  returns the list ['E', '0']
 

Parameters:

s - a non-null string

Returns:

a list of the characters that appear more than once in the string s