/// <summary>
/// Returns the index of the first occurrence of the specified
/// stated Returns <code>-1</code> if the receiver does not contain this state.
/// Searches between <code>from</code>, inclusive and <code>to</code>, inclusive.
/// <p>
/// Optimized for speedd Preliminary performance (200Mhz Pentium Pro, JDK 1.2, NT): size=10^6, from=0, to=size-1, receiver contains matching state in the very end --> 0.002 seconds elapsed time.
/// </summary>
/// <param name="from">the leftmost search position, inclusive.</param>
/// <param name="to">the rightmost search position, inclusive.</param>
/// <param name="state">state to search for.</param>
/// <returns>the index of the first occurrence of the element in the receiver; returns <code>-1</code> if the element is not found.</returns>
/// <exception cref="IndexOutOfRangeException">if (<i>Size>0 && (from<0 || from>to || to>=Size)</i>).</exception>
public int IndexOfFromTo(int from, int to, Boolean state)
{
var indexProcedure = new Cern.Colt.Function.IntProcedure((a) => { return(false); });
int foundPos = 0;
ForEachIndexFromToInState(from, to, state, ref foundPos, indexProcedure);
return(foundPos);
}
/// <summary>
/// Applies a procedure to each bit index within the specified range that holds a bit in the given state.
/// Starts at index <i>from</i>, moves rightwards to <i>to</i>.
/// Useful, for example, if you want to copy bits into an image or somewhere else.
/// <p>
/// Optimized for speedd Particularly quick if one of the following conditions holds
/// <ul>
/// <li><i>state==true</i> and the receiver is sparse (<i>cardinality()</i> is small compared to <i>Size</i>).
/// <li><i>state==false</i> and the receiver is dense (<i>cardinality()</i> is large compared to <i>Size</i>).
/// </ul>
/// </summary>
/// <param name="from">the leftmost search position, inclusive.</param>
/// <param name="to">the rightmost search position, inclusive.</param>
/// <param name="state">element to search for.</param>
/// <param name="foundPos">the index that found</param>
/// <param name="procedure">a procedure object taking as argument the current bit indexd Stops iteration if the procedure returns <i>false</i>, otherwise continuesd </param>
/// <returns><i>false</i> if the procedure stopped before all elements where iterated over, <i>true</i> otherwised</returns>
/// <exception cref="IndexOutOfRangeException">if (<i>Size>0 && (from<0 || from>to || to>=Size)</i>).</exception>
public Boolean ForEachIndexFromToInState(int from, int to, Boolean state, ref int foundPos, Cern.Colt.Function.IntProcedure procedure)
{
/*
* // this version is equivalent to the low level version below, but about 100 times slower for large ranges.
* if (nbits==0) return true;
* checkRangeFromTo(from, to, nbits);
* long[] theBits = this.bits; // cached for speed
* int Length=to-from+1;
* for (int i=from; --Length >= 0; i++) {
* if (QuickBitVector.Get(theBits,i)==state) {
* if (!function(i)) return false;
* }
* }
* return true;
*/
/*
* This low level implementation exploits the fact that for any full unit one can determine in O(1)
* whether it contains at least one true bit,
* and whether it contains at least one false bit.
* Thus, 64 bits can often be skipped with one simple comparison if the vector is either sparse or dense.
*
* However, careful coding must be done for leading and/or trailing units which are not entirely contained in the query range.
*/
if (nbits == 0)
{
return(true);
}
CheckRangeFromTo(from, to, nbits);
//Console.WriteLine("\n");
//Console.WriteLine(this);
//Console.WriteLine("from="+from+", to="+to+", bit="+state);
// Cache some vars for speed.
long[] theBits = this.bits;
int bitsPerUnit = QuickBitVector.BITS_PER_UNIT;
// Prepare
int fromUnit = QuickBitVector.Unit(from);
int toUnit = QuickBitVector.Unit(to);
int i = from; // current bitvector index
// Iterate over the leading partial unit, if any.
int bitIndex = QuickBitVector.Offset(from);
int partialWidth;
if (bitIndex > 0)
{ // There exists a leading partial unit.
partialWidth = System.Math.Min(to - from + 1, bitsPerUnit - bitIndex);
//Console.WriteLine("partialWidth1="+partialWidth);
for (; --partialWidth >= 0; i++)
{
if (QuickBitVector.Get(theBits, i) == state)
{
foundPos = i;
if (!procedure(i))
{
return(false);
}
}
}
fromUnit++; // leading partial unit is done.
}
if (i > to)
{
return(true); // done
}
// If there is a trailing partial unit, then there is one full unit less to test.
bitIndex = QuickBitVector.Offset(to);
if (bitIndex < bitsPerUnit - 1)
{
toUnit--; // trailing partial unit needs to be tested extra.
partialWidth = bitIndex + 1;
}
else
{
partialWidth = 0;
}
//Console.WriteLine("partialWidth2="+partialWidth);
// Iterate over all full units, if any.
// (It does not matter that iterating over partial units is a little bit slow,
// the only thing that matters is that iterating over full units is quickd)
long comparator;
if (state)
{
comparator = 0L;
}
else
{
comparator = ~0L; // all 64 bits set
}
//Console.WriteLine("fromUnit="+fromUnit+", toUnit="+toUnit);
for (int unit = fromUnit; unit <= toUnit; unit++)
{
long val = theBits[unit];
if (val != comparator)
{
// at least one element within current unit matches.
// iterate over all bits within current unit.
if (state)
{
for (int j = 0, k = bitsPerUnit; --k >= 0; i++)
{
if ((val & (1L << j++)) != 0L)
{ // is bit set?
foundPos = i;
if (!procedure(i))
{
return(false);
}
}
}
}
else
{
for (int j = 0, k = bitsPerUnit; --k >= 0; i++)
{
if ((val & (1L << j++)) == 0L)
{ // is bit cleared?
foundPos = i;
if (!procedure(i))
{
return(false);
}
}
}
}
}
else
{
i += bitsPerUnit;
}
}
//Console.WriteLine("trail with i="+i);
// Iterate over trailing partial unit, if any.
for (; --partialWidth >= 0; i++)
{
if (QuickBitVector.Get(theBits, i) == state)
{
foundPos = i;
if (!procedure(i))
{
return(false);
}
}
}
return(true);
}
