KnapsackItem (JaCoP 4.9.0 API)

java.lang.Object
- org.jacop.constraints.knapsack.KnapsackItem

All Implemented Interfaces:

Comparable<KnapsackItem>
```
public final class KnapsackItem
extends Object
implements Comparable<KnapsackItem>
```
This class stores information about items being considered by a Knapsack constraint. It is a holder for integer attributes like weight and profit, as well as finite domain variable denoting the quantity being taken. It also stores precomputed efficiency of the item.
It implements comparable interface in such a away so that items can be sorted in decreasing efficiency. In case of equal efficiency then item which is heavier is preferred.

Version:

4.9

Author:

Radoslaw Szymanek and Wadeck Follonier

Field Summary

Fields
Modifier and Type	Field and Description
`double`	`efficiency` It stores information about the item efficiency - profit/weight.
`int`	`profit` It specifies the profit of a single instance of this item.
`IntVar`	`quantity` It is a finite domain variable specifying the possible quantity of that item.
`int`	`weight` It specifies the weight of a single instance of this item.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`compareTo(KnapsackItem that)` Method used in the sorting of the items, we use profit and weight to know the less efficient item without using division.
`double`	`getEfficiency()` It returns an efficiency of that item.
`int`	`getProfit()` It returns a profit of a single instance of that item.
`IntVar`	`getVariable()` t returns quantity variable associated with that item.
`int`	`getWeight()` It returns a weight of a single instance of that item.
`String`	`toString()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

- Field Detail
  - quantity
```
public final IntVar quantity
```
    It is a finite domain variable specifying the possible quantity of that item.
  - weight
```
public final int weight
```
    It specifies the weight of a single instance of this item.
  - profit
```
public final int profit
```
    It specifies the profit of a single instance of this item.
  - efficiency
```
public final double efficiency
```
    It stores information about the item efficiency - profit/weight.
- Method Detail
  - compareTo
```
public int compareTo(KnapsackItem that)
```
    Method used in the sorting of the items, we use profit and weight to know the less efficient item without using division. This function returns 1 if this item is less efficient than that item. This function returns -1 if this item is more efficient than that item. If both items are equally efficient then this function returns 1 if this item has smaller weight than that item.
    In connection with Arrays.sort() it will produce items from most efficient to least efficient breaking ties in the favor of the larger weight.
    
    Specified by:
    
    compareTo in interface Comparable<KnapsackItem>
  - getVariable
```
public final IntVar getVariable()
```
    t returns quantity variable associated with that item.
    
    Returns:
    
    quantity finite domain variable.
  - getProfit
```
public final int getProfit()
```
    It returns a profit of a single instance of that item.
    
    Returns:
    
    profit of a single instance of that item.
  - getWeight
```
public final int getWeight()
```
    It returns a weight of a single instance of that item.
    
    Returns:
    
    weight of a single instance of that item.
  - getEfficiency
```
public final double getEfficiency()
```
    It returns an efficiency of that item.
    
    Returns:
    
    the efficiency of that item.
  - toString
```
public String toString()
```
    Overrides:
    
    toString in class Object

Class KnapsackItem

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

quantity

weight

profit

efficiency

Method Detail

compareTo

getVariable

getProfit

getWeight

getEfficiency

toString