Type Parameters:

E - the type of elements in this priority queue.

All Known Implementing Classes:

DoubleMapMinPQ, HeapMinPQ, OptimizedHeapMinPQ, UnsortedArrayMinPQ
```
public interface MinPQ<E>
```
Priority queue where objects have extrinsic priority. Whereas PriorityQueue relies on Comparable objects (or a Comparator), this interface requires priority values represented using double values. Elements must be unique, but priority values do not need to be unique.

See Also:

DoubleMapMinPQ, UnsortedArrayMinPQ, HeapMinPQ, OptimizedHeapMinPQ

Method Summary

All Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method	Description
`void`	`add(E element, double priority)`	Adds an element with the given priority value.
`void`	`changePriority(E element, double priority)`	Updates the given elements' associated priority value.
`boolean`	`contains(E element)`	Returns true if the given element is in this priority queue.
`default boolean`	`isEmpty()`	Returns true if this priority queue contains no elements.
`E`	`peekMin()`	Returns the element with the minimum priority value.
`E`	`removeMin()`	Returns and removes the element with the minimum priority value.
`int`	`size()`	Returns the number of elements in this priority queue.

- Method Detail
  - add
```
void add(E element,
         double priority)
```
    Adds an element with the given priority value.
    
    Parameters:
    
    element - the element to add.
    
    priority - the priority value for the element.
    
    Throws:
    
    IllegalArgumentException - if element is null or already present.
  - contains
```
boolean contains(E element)
```
    Returns true if the given element is in this priority queue.
    
    Parameters:
    
    element - element to be checked for containment.
    
    Returns:
    
    true if the given element is in this priority queue.
  - peekMin
```
E peekMin()
```
    Returns the element with the minimum priority value.
    
    Returns:
    
    the element with the minimum priority value.
    
    Throws:
    
    NoSuchElementException - if this priority queue is empty.
  - removeMin
```
E removeMin()
```
    Returns and removes the element with the minimum priority value.
    
    Returns:
    
    the element with the minimum priority value.
    
    Throws:
    
    NoSuchElementException - if this priority queue is empty.
  - changePriority
```
void changePriority(E element,
                    double priority)
```
    Updates the given elements' associated priority value.
    
    Parameters:
    
    element - the element whose associated priority value should be modified.
    
    priority - the updated priority value.
    
    Throws:
    
    NoSuchElementException - if the element is not present.
  - size
```
int size()
```
    Returns the number of elements in this priority queue.
    
    Returns:
    
    the number of elements in this priority queue.
  - isEmpty
```
default boolean isEmpty()
```
    Returns true if this priority queue contains no elements.
    
    Returns:
    
    true if this priority queue contains no elements.

Interface MinPQ<E>

Method Summary

Method Detail

add

contains

peekMin

removeMin

changePriority

size

isEmpty