/// <summary>
/// Uses a binary search algorithm to quickly determine the collection of the
/// <see cref="ICollectionBlock{TKey,TValue}"/> within 'blocks' of the block
/// that contains the given key value using the <see cref="ISortComparer{TKey,TValue}"/>
/// as a lookup comparator.
/// </summary>
/// <param name="key"></param>
/// <param name="comparer"></param>
/// <returns></returns>
private int FindBlockContaining(TKey key, ISortComparer <TKey, TValue> comparer)
{
if (Count == 0)
{
return(-1);
}
int low = 0;
int high = Blocks.Count - 1;
while (low <= high)
{
int mid = (low + high) / 2;
var block = Blocks[mid];
// Is what we are searching for lower than the bottom value?
if (comparer.Compare(block.Bottom, key) > 0)
{
high = mid - 1;
}
// No, then is it greater than the highest value?
else if (comparer.Compare(block.Top, key) < 0)
{
low = mid + 1;
}
// Must be inside this block then!
else
{
return(mid);
}
}
return(-(low + 1)); // key not found.
}
/// <summary>
/// Uses a binary search algorithm to quickly determine the collection of
/// the <see cref="ICollectionBlock{TKey,TValue}"/> within 'blocks' of the block
/// that contains the given key value using the <see cref="ISortComparer{TKey,TValue}"/>
/// as a lookup comparator.
/// </summary>
/// <param name="key"></param>
/// <param name="comparer"></param>
/// <returns></returns>
private int FindLastBlock(TKey key, ISortComparer <TKey, TValue> comparer)
{
if (Count == 0)
{
return(-1);
}
int low = 0;
int high = Blocks.Count - 1;
while (low <= high)
{
if (high - low <= 2)
{
for (int i = high; i >= low; --i)
{
var block1 = Blocks[i];
if (comparer.Compare(block1.Bottom, key) <= 0)
{
if (comparer.Compare(block1.Top, key) >= 0)
{
return(i);
}
return(-(i + 1) - 1);
}
}
return(-(low + 1));
}
int mid = (low + high) / 2;
var block = Blocks[mid];
// Is what we are searching for lower than the bottom value?
if (comparer.Compare(block.Bottom, key) > 0)
{
high = mid - 1;
}
// No, then is it greater than the highest value?
else if (comparer.Compare(block.Top, key) < 0)
{
low = mid + 1;
}
// Equal, so highest must be someplace between mid and high.
else
{
low = mid;
if (low == high)
{
return(low);
}
}
}
return(-(low + 1)); // key not found.
}
/// <inheritdoc/>
public long BinarySearch(TKey key, ISortComparer <TKey, TValue> comparer)
{
var arr = GetArray(true);
long low = 0;
long high = count - 1;
while (low <= high)
{
var mid = (low + high) / 2;
int cmp = comparer.Compare(arr[mid], key);
if (cmp < 0)
{
low = mid + 1;
}
else if (cmp > 0)
{
high = mid - 1;
}
else
{
return(mid); // key found
}
}
return(-(low + 1)); // key not found.
}
/// <inheritdoc/>
public long SearchFirst(TKey key, ISortComparer <TKey, TValue> comparer)
{
var arr = GetArray(true);
long low = 0;
long high = count - 1;
while (low <= high)
{
if (high - low <= 2)
{
for (var i = low; i <= high; ++i)
{
int cmp1 = comparer.Compare(arr[i], key);
if (cmp1 == 0)
{
return(i);
}
if (cmp1 > 0)
{
return(-(i + 1));
}
}
return(-(high + 2));
}
var mid = (low + high) / 2;
int cmp = comparer.Compare(arr[mid], key);
if (cmp < 0)
{
low = mid + 1;
}
else if (cmp > 0)
{
high = mid - 1;
}
else
{
high = mid;
}
}
return(-(low + 1)); // key not found.
}
/// <summary>
/// Compare!
/// </summary>
/// <param name="x"></param>
/// <param name="y"></param>
/// <returns></returns>
public override int Compare(object x, object y)
{
string x1 = ((ListViewItem)x).SubItems[col].Text;
string y1 = ((ListViewItem)y).SubItems[col].Text;
if (comparer == null)
{
// Default is the StringComparer
ISortComparer c = new Yaowi.Common.Collections.StringComparer();
c.SortOrder = sortorder;
return(c.Compare(x1, y1));
}
else
{
comparer.SortOrder = sortorder;
return(comparer.Compare(x1, y1));
}
}
