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Class rebelsky.util.IntegerArrayAlgorithms
java.lang.Object

+rebelsky.util.IntegerArrayAlgorithms
 public class IntegerArrayAlgorithms
 extends Object
A collection of algorithms appropriate for arrays of integers. While
this class was originally designed to support an exercise in
algorithm measurement, it is hoped that it has other uses.
 Version:
 1.0 of February 1998
 Author:
 Samuel A. Rebelsky
Constructor Index
 o
IntegerArrayAlgorithms()

Method Index
 o
binarySearch(int[], int)
 Search a sorted array of integers for a particular value.
 o
bubbleSort(int[])
 Sort an array of integers by "bubbling" values up the array.
 o
indexOfSmallest(int[])
 Find the position of the smallest element in an array
of integers.
 o
indexOfSmallest(int[], int)
 Find the position of the smallest element in a subrange
of an array of integers.
 o
indexOfSmallest(int[], int, int)
 Find the position of the smallest element in a subrange
of an array of integers.
 o
random(int)
 Create an array of integers of size n with the population of
the array being "random".
 o
random(int, int)
 Create an array of nonnegative integers of size n with the
population of the array being "random" and the values
between 0 ...
 o
selectionSort(int[])
 Sort an array of integers using the selection sort algorithm,
in which the smallest remaining element is repeatedly identified
and moved to the front of the list.
 o
sequentialSearch(int[], int)
 Search through an unsorted array of integers to determine whether
a particular value (key) is in the array.
 o
swap(int[], int, int)
 Swap the elements at positions a and b in an integer array.
Constructors
o
IntegerArrayAlgorithms
public IntegerArrayAlgorithms()
Methods
o
binarySearch
public static boolean binarySearch(int iarr[],
int key)
 Search a sorted array of integers for a particular value.
pre: The array is sorted in increasing order.
pre: The array is nonempty.
post: The array is not affected.
 Returns:
 true if the value is in the array; false otherwise.
o
bubbleSort
public static int[] bubbleSort(int iarr[])
 Sort an array of integers by "bubbling" values up the array.
pre: (none)
post: the original array is unmodified.
post: for 0 <= i < length1, sorted[i] <= sorted[i+1]
post: if element x appears n times in the original array,
it also appears n times in the sorted array
post: the sorted array has the same length as the original
array.
 Returns:
 a sorted version of the original array.
o
indexOfSmallest
public static int indexOfSmallest(int iarr[])
 Find the position of the smallest element in an array
of integers.
pre: The array is nonempty.
post: The array is unaffected.
post: The index smallest element is returned.
 Returns:
 x s.t. iarr[x] <= iarr[i] for all 0 <= i < iarr.length
o
indexOfSmallest
public static int indexOfSmallest(int iarr[],
int lb)
 Find the position of the smallest element in a subrange
of an array of integers.
pre: The subrange is nonempty.
post: The array is unaffected.
post: The index smallest element is returned.
 Returns:
 x s.t. iarr[x] <= iarr[i] for all lb <= i < iarr.length
o
indexOfSmallest
public static int indexOfSmallest(int iarr[],
int lb,
int ub)
 Find the position of the smallest element in a subrange
of an array of integers.
pre: The subrange is nonempty.
post: The array is unaffected.
post: The index smallest element is returned.
 Returns:
 x s.t. iarr[x] <= iarr[i] for all lb <= i <= ub
o
random
public static int[] random(int size,
int bound) throws Exception
 Create an array of nonnegative integers of size n with the
population of the array being "random" and the values
between 0 ... bound.
pre: n >= 0
pre: bound >= 0
post: a newlyallocated array of size n is returned
Example (10 integers between 0 and 100):
int[] stuff = IntegerArrayAlgorithms.random(10,100);
 Throws: Exception
 When the preconditions are not met.
o
random
public static int[] random(int size) throws Exception
 Create an array of integers of size n with the population of
the array being "random".
pre: n >= 0
post: a newlyallocated array of size n is returned
Example:
int[] stuff = IntegerArrayAlgorithms.random(10);
 Throws: Exception
 when
size < 0
o
selectionSort
public static int[] selectionSort(int iarr[])
 Sort an array of integers using the selection sort algorithm,
in which the smallest remaining element is repeatedly identified
and moved to the front of the list.
pre: (none)
post: the original array is unmodified.
post: for 0 <= i < length1, sorted[i] <= sorted[i+1]
post: if element x appears n times in the original array,
it also appears n times in the sorted array
array.
o
sequentialSearch
public static boolean sequentialSearch(int iarr[],
int key)
 Search through an unsorted array of integers to determine whether
a particular value (key) is in the array.
pre: (none)
post: the array is unaffected
 Returns:
 true if the key is in the array; false otherwise.
o
swap
public static void swap(int iarr[],
int a,
int b)
 Swap the elements at positions a and b in an integer array.
pre: 0 <= a,b < iarr.length
pre: the array is nonempty
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