在C#中,PriorityQueue类没有内置的方法来处理优先级反转问题。但是,你可以通过维护一个最小堆(min-heap)来实现优先级队列,并在插入和删除元素时手动处理优先级反转问题。
以下是一个简单的示例,展示了如何在C#中实现一个支持优先级反转处理的优先级队列:
using System;
using System.Collections.Generic;
public class PriorityQueue where T : IComparable
{
private List _elements = new List();
public void Enqueue(T item, int priority)
{
var node = new Node(item, priority);
int index = _elements.BinarySearch(node, Comparer>.Create((x, y) => x.Priority.CompareTo(y.Priority)));
if (index < 0)
{
index = ~index;
}
_elements.Insert(index, node);
// Rebalance the heap
while (index > 0 && _elements[(index - 1) / 2].Priority > node.Priority)
{
Swap(_elements, index, (index - 1) / 2);
index = (index - 1) / 2;
}
}
public T Dequeue()
{
if (_elements.Count == 0)
{
throw new InvalidOperationException("The priority queue is empty.");
}
var min = _elements[0];
_elements[0] = _elements[_elements.Count - 1];
_elements.RemoveAt(_elements.Count - 1);
// Rebalance the heap
int index = 0;
while (true)
{
int leftChildIndex = 2 * index + 1;
int rightChildIndex = 2 * index + 2;
int smallestChildIndex = -1;
if (leftChildIndex < _elements.Count && _elements[leftChildIndex].Priority < _elements[smallestChildIndex].Priority)
{
smallestChildIndex = leftChildIndex;
}
if (rightChildIndex < _elements.Count && _elements[rightChildIndex].Priority < _elements[smallestChildIndex].Priority)
{
smallestChildIndex = rightChildIndex;
}
if (smallestChildIndex == -1)
{
break;
}
Swap(_elements, index, smallestChildIndex);
index = smallestChildIndex;
}
return min;
}
private void Swap(List list, int i, int j)
{
T temp = list[i];
list[i] = list[j];
list[j] = temp;
}
}
public class Node
{
public T Item { get; }
public int Priority { get; }
public Node(T item, int priority)
{
Item = item;
Priority = priority;
}
}
在这个示例中,我们定义了一个泛型类PriorityQueue
,它接受一个实现了IComparable
接口的类型参数。我们使用一个List
来存储元素,并在插入和删除元素时手动维护堆的平衡。这样,我们可以确保优先级最高的元素始终位于堆的顶部。