test4

Class Test4B

java.lang.Object

test4.Test4B

public class Test4B
extends Object

Constructor Summary

Constructors

Constructor and Description
Test4B()

Method Summary

Modifier and Type	Method and Description
static String	countTo(int from, int to) Returns the string formed by counting starting at from up to and including to in increments of 1.
static int	findZero(List<Integer> t) Returns the index of the element equal to zero in the specified sorted list.
static void	unique(List<String> t) Removes all duplicated strings from a sorted list of strings maintaining the sorted order of the strings.
static String	zipper(String s, String t) Given two non-null strings of equal length, returns the string formed by alternating characters from s and t.

Methods inherited from class java.lang.Object

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

Constructor Detail

Test4B

public Test4B()

Method Detail

countTo

public static String countTo(int from,
                             int to)

Returns the string formed by counting starting at from up to and including to in increments of 1. Each number in the string is separated from the next number by a comma and a space.

 countTo(1, 1)    returns the string equal to "1"
 countTo(5, 6)    returns the string equal to "5, 6"
 countTo(10, 12)  returns the string equal to "10, 11, 12"
 

Parameters:

from - the number to count from

to - the number to count to

Returns:

the string formed by repeating the specified string n times

Precondition:

from is less than or equal to to

zipper

public static String zipper(String s,
                            String t)

Given two non-null strings of equal length, returns the string formed by alternating characters from s and t. For example:

 zipper("", "") returns the empty string
 zipper("a", "1") returns the string "a1"
 zipper("abcd", "1234") returns the string "a1b2c3d4"
 

Parameters:

s - a string of length n

t - a second string of length n

Returns:

the string of length 2n formed by alternating characters of s and t

unique

public static void unique(List<String> t)

Removes all duplicated strings from a sorted list of strings maintaining the sorted order of the strings. If the list contains unique strings then the list remains unchanged. For example, if t is the list ["a", "b", "c", "d"] then unique(t) would do nothing. If t is the list ["w", "w", "w", "x", "y", "y", "z"] then unique(t) would modify t so that it became the list ["w", "x", "y", "z"].

Parameters:

t - a sorted list of strings that the method modifies so that it contains no duplicated strings (and the list remains in sorted order).

findZero

public static int findZero(List<Integer> t)

Returns the index of the element equal to zero in the specified sorted list. The list t may be sorted in either ascending or descending order. The list t is not modified by this method.

The computational complexity of the method is O(log n) where n is the size of the list t.

Parameters:

t - a sorted list

Returns:

the index of the element equal to zero

Precondition:

the list is sorted in either ascending or descending order and the list contains zero