org.apache.mahout.math

Class BinarySearch

java.lang.Object

org.apache.mahout.math.BinarySearch

public final class BinarySearch
extends Object

Method Summary

Methods

Modifier and Type	Method and Description
static int	binarySearchFromTo(byte[] array, byte value, int from, int to) Performs a binary search for the specified element in the specified ascending sorted array.
static int	binarySearchFromTo(char[] array, char value, int from, int to) Performs a binary search for the specified element in the specified ascending sorted array.
static int	binarySearchFromTo(double[] array, double value, int from, int to) Performs a binary search for the specified element in the specified ascending sorted array.
static int	binarySearchFromTo(float[] array, float value, int from, int to) Performs a binary search for the specified element in the specified ascending sorted array.
static int	binarySearchFromTo(int[] array, int value, int from, int to) Performs a binary search for the specified element in the specified ascending sorted array.
static int	binarySearchFromTo(long[] array, long value, int from, int to) Performs a binary search for the specified element in the specified ascending sorted array.
static int	binarySearchFromTo(short[] array, short value, int from, int to) Performs a binary search for the specified element in the specified ascending sorted array.
static <T extends Comparable<T>> int	binarySearchFromTo(T[] array, T object, int from, int to) Performs a binary search for the specified element in the specified ascending sorted array.
static <T> int	binarySearchFromTo(T[] array, T object, int from, int to, Comparator<? super T> comparator) Performs a binary search for the specified element in the specified ascending sorted array using the Comparator to compare elements.

Methods inherited from class java.lang.Object

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

Method Detail

binarySearchFromTo

public static int binarySearchFromTo(byte[] array,
                     byte value,
                     int from,
                     int to)

Performs a binary search for the specified element in the specified ascending sorted array. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters:

array - the sorted byte array to search.

value - the byte element to find.

from - the first index to sort, inclusive.

to - the last index to sort, inclusive.

Returns:

the non-negative index of the element, or a negative index which is -index - 1 where the element would be inserted.

binarySearchFromTo

public static int binarySearchFromTo(char[] array,
                     char value,
                     int from,
                     int to)

Performs a binary search for the specified element in the specified ascending sorted array. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters:

array - the sorted char array to search.

value - the char element to find.

from - the first index to sort, inclusive.

to - the last index to sort, inclusive.

Returns:

the non-negative index of the element, or a negative index which is -index - 1 where the element would be inserted.

binarySearchFromTo

public static int binarySearchFromTo(double[] array,
                     double value,
                     int from,
                     int to)

Performs a binary search for the specified element in the specified ascending sorted array. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters:

array - the sorted double array to search.

value - the double element to find.

from - the first index to sort, inclusive.

to - the last index to sort, inclusive.

Returns:

the non-negative index of the element, or a negative index which is -index - 1 where the element would be inserted.

binarySearchFromTo

public static int binarySearchFromTo(float[] array,
                     float value,
                     int from,
                     int to)

Performs a binary search for the specified element in the specified ascending sorted array. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters:

array - the sorted float array to search.

value - the float element to find.

from - the first index to sort, inclusive.

to - the last index to sort, inclusive.

Returns:

the non-negative index of the element, or a negative index which is -index - 1 where the element would be inserted.

binarySearchFromTo

public static int binarySearchFromTo(int[] array,
                     int value,
                     int from,
                     int to)

Performs a binary search for the specified element in the specified ascending sorted array. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters:

array - the sorted int array to search.

value - the int element to find.

from - the first index to sort, inclusive.

to - the last index to sort, inclusive.

Returns:

the non-negative index of the element, or a negative index which is -index - 1 where the element would be inserted.

binarySearchFromTo

public static int binarySearchFromTo(long[] array,
                     long value,
                     int from,
                     int to)

Performs a binary search for the specified element in the specified ascending sorted array. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters:

array - the sorted long array to search.

value - the long element to find.

from - the first index to sort, inclusive.

to - the last index to sort, inclusive.

Returns:

the non-negative index of the element, or a negative index which is -index - 1 where the element would be inserted.

binarySearchFromTo

public static <T extends Comparable<T>> int binarySearchFromTo(T[] array,
                                               T object,
                                               int from,
                                               int to)

Performs a binary search for the specified element in the specified ascending sorted array. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters:

array - the sorted Object array to search.

object - the Object element to find

from - the first index to sort, inclusive.

to - the last index to sort, inclusive.

Returns:

the non-negative index of the element, or a negative index which is -index - 1 where the element would be inserted.

binarySearchFromTo

public static <T> int binarySearchFromTo(T[] array,
                         T object,
                         int from,
                         int to,
                         Comparator<? super T> comparator)

Performs a binary search for the specified element in the specified ascending sorted array using the Comparator to compare elements. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters:

array - the sorted array to search

object - the element to find

from - the first index to sort, inclusive.

to - the last index to sort, inclusive.

comparator - the Comparator used to compare the elements.

Returns:

the non-negative index of the element, or a negative index which

binarySearchFromTo

public static int binarySearchFromTo(short[] array,
                     short value,
                     int from,
                     int to)

Performs a binary search for the specified element in the specified ascending sorted array. Searching in an unsorted array has an undefined result. It's also undefined which element is found if there are multiple occurrences of the same element.

Parameters:

array - the sorted short array to search.

value - the short element to find.

from - the first index to sort, inclusive.

to - the last index to sort, inclusive.

Returns:

the non-negative index of the element, or a negative index which is -index - 1 where the element would be inserted.