只是一个快速的笔记,这不是功课.我只是想刷新我的算法.我在C#中使用MergeSort来编写一个可以根据泛型进行排序的递归方法：
class SortAlgorithms
{
public T[] MergeSort<T> (T[] unsortedArray) where T : System.IComparable<T>
{
T[] left,right;
int middle = unsortedArray.Length / 2;
left = new T[middle];
right = new T[unsortedArray.Length - middle];
if (unsortedArray.Length <= 1)
return unsortedArray;
for (int i = 0; i < middle; i++)
{
left[i] = unsortedArray[i];
}
for (int i = middle; i < unsortedArray.Length; i++)
{
right[i - middle] = unsortedArray[i];
}
left = MergeSort(left);
right = MergeSort(right);
return Merge<T>(left,right);
}
private T[] Merge<T> (T[] left,T[] right) where T : System.IComparable<T>
{
T[] result = new T[left.Length + right.Length];
int currentElement = 0;
while (left.Length > 0 || right.Length > 0)
{
if (left.Length > 0 && right.Length > 0)
{
if (left[0].CompareTo(right[0]) < 0)
{
result[currentElement] = left[0];
left = left.Skip(1).ToArray();
currentElement++;
}
else
{
result[currentElement] = right[0];
right = right.Skip(1).ToArray();
currentElement++;
}
}
else if (left.Length > 0)
{
result[currentElement] = left[0];
left = left.Skip(1).ToArray();
currentElement++;
}
else if (right.Length > 0)
{
result[currentElement] = right[0];
right = right.Skip(1).ToArray();
currentElement++;
}
}
return result;
}
}
这是有效的,但它是痛苦的慢.我使用System.Diagnostic.StopWatch来检查Array.Sort(使用QuickSort算法)的性能与我的MergeSort进行比较,差异是非常重要的,我想知道是否可能我正在实现这个错误.任何意见？
