Package it.unimi.dsi.law.big.util

Class IntegerExchangeCounter

java.lang.Object

it.unimi.dsi.law.big.util.IntegerExchangeCounter

public class IntegerExchangeCounter
extends Object

Computes the number of discordances between two integer score big vectors using Knight's O(n log n) MergeSort-based algorithm.

This class is just a copy of ExchangeCounter using integer big vectors.

See Also:

ExchangeCounter

Constructor Summary

Constructors

Constructor	Description
IntegerExchangeCounter(long[][] perm, int[][] v)	Creates a new exchange counter.
IntegerExchangeCounter(long[][] perm, int[][] v, long[][] support)	Creates a new exchange counter with a provided support big array.

Method Summary

Modifier and Type	Method	Description
long	count()	Computes the number of exchanges.

Methods inherited from class java.lang.Object

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

Constructor Details

IntegerExchangeCounter

public IntegerExchangeCounter(long[][] perm,
int[][] v,
long[][] support)

Creates a new exchange counter with a provided support big array.

This constructor avoids the need to allocate a support big array, in case one is already available.

Parameters:

perm - the big array to be sorted.

v - the score integer big vector used to compare the element of perm.

support - a big array that will be used as temporary storage during the computation (its content will be erased); must be at least as long as a.

IntegerExchangeCounter

public IntegerExchangeCounter(long[][] perm,
int[][] v)

Creates a new exchange counter.

Parameters:

perm - the big array to be sorted.

v - the score integer big vector used to compare the element of perm.

Method Details

count

public long count()

Computes the number of exchanges.

Note that a call to this method will actually sort the permutation at creation time.

Returns:

the number of exchanges that will order the permutation provided at creation time using the score vector provided at creation time.