static int Decoding(FrequencyNode root, string encodedValue, int index)
{
if (root.IsLeaf)
{
Console.Write(root.Char);
return(index);
}
if (encodedValue[index] == '0')
{
return(Decoding(root.Left, encodedValue, index + 1));
}
else
{
return(Decoding(root.Right, encodedValue, index + 1));
}
}
static void AssignCode(FrequencyNode root, string prefix)
{
if (root.IsLeaf)
{
root.StringCode = prefix;
return;
}
if (root.Left != null)
{
AssignCode(root.Left, prefix + "0");
}
if (root.Right != null)
{
AssignCode(root.Right, prefix + "1");
}
}
public long IncrementBy(int value)
{
if (value == 0)
return Value;
if (value < 1)
throw new ArgumentOutOfRangeException("value");
int timeValue = GetTimeValue();
FrequencyNode currentHead = this.head;
while (currentHead == null || currentHead.TimeValue < timeValue)
{
// The head node is out of date or we're empty so we need to
// create a new node to take it's place. We'll populate the sample count
// up-front since we're the only one who's got access to the node
var newHeadNode = new FrequencyNode { TimeValue = timeValue };
RuntimeHelpers.PrepareConstrainedRegions();
try { }
finally
{
// Try to update the head reference to our newly created node.
// If we fail we'll just try again since most likely someone else
// managed to update the node before us and we can use that instead.
if (Interlocked.CompareExchange(ref this.head, newHeadNode, currentHead) == currentHead)
{
// Succeeded in setting the head reference.
// If we weren't empty before we need to update the previous
// head node so that it references the new head.
if (currentHead != null)
currentHead.Next = newHeadNode;
// If the tail node reference is null we'll update it to point to
// our new head node.
Interlocked.CompareExchange(ref this.tail, newHeadNode, null);
currentHead = newHeadNode;
}
else
{
// Prepare for a retry
currentHead = this.head;
}
}
}
RuntimeHelpers.PrepareConstrainedRegions();
try { }
finally
{
Interlocked.Add(ref currentHead.Samples, value);
Interlocked.Add(ref this.counterValue, value);
}
Prune(currentHead.TimeValue);
return Interlocked.Read(ref this.counterValue);
}
public long IncrementBy(int value)
{
if (value == 0)
{
return(Value);
}
if (value < 1)
{
throw new ArgumentOutOfRangeException("value");
}
int timeValue = GetTimeValue();
FrequencyNode currentHead = this.head;
while (currentHead == null || currentHead.TimeValue < timeValue)
{
// The head node is out of date or we're empty so we need to
// create a new node to take it's place. We'll populate the sample count
// up-front since we're the only one who's got access to the node
var newHeadNode = new FrequencyNode {
TimeValue = timeValue
};
RuntimeHelpers.PrepareConstrainedRegions();
try { }
finally
{
// Try to update the head reference to our newly created node.
// If we fail we'll just try again since most likely someone else
// managed to update the node before us and we can use that instead.
if (Interlocked.CompareExchange(ref this.head, newHeadNode, currentHead) == currentHead)
{
// Succeeded in setting the head reference.
// If we weren't empty before we need to update the previous
// head node so that it references the new head.
if (currentHead != null)
{
currentHead.Next = newHeadNode;
}
// If the tail node reference is null we'll update it to point to
// our new head node.
Interlocked.CompareExchange(ref this.tail, newHeadNode, null);
currentHead = newHeadNode;
}
else
{
// Prepare for a retry
currentHead = this.head;
}
}
}
RuntimeHelpers.PrepareConstrainedRegions();
try { }
finally
{
Interlocked.Add(ref currentHead.Samples, value);
Interlocked.Add(ref this.counterValue, value);
}
Prune(currentHead.TimeValue);
return(Interlocked.Read(ref this.counterValue));
}
public static void Test()
{
string text = "My names is Marco Rossignoli and I live in Italy";
Console.WriteLine($"To encode {text} initial len {text.Length}");
Dictionary <char, int> frequencyTable = new Dictionary <char, int>();
for (int i = 0; i < text.Length; i++)
{
if (!frequencyTable.ContainsKey(text[i]))
{
frequencyTable.Add(text[i], 0);
}
frequencyTable[text[i]]++;
}
FrequencyNode[] frequencyTableList = frequencyTable.OrderBy(v => v.Value).Select(k => new FrequencyNode()
{
FrequencyValue = k.Value, Char = k.Key
}).ToArray();
FrequencyNode[] ft = frequencyTableList.ToArray();
foreach (var v in ft)
{
Console.WriteLine($"{v.Char} {v.FrequencyValue}");
}
while (ft.Length > 1)
{
FrequencyNode node = new FrequencyNode()
{
FrequencyValue = ft[0].FrequencyValue + ft[1].FrequencyValue
};
if (ft[0].FrequencyValue < ft[1].FrequencyValue)
{
node.Left = ft[0];
node.Right = ft[1];
}
else
{
node.Left = ft[1];
node.Right = ft[0];
}
var tmp = new List <FrequencyNode>(ft.Skip(2).ToArray());
tmp.Add(node);
ft = tmp.OrderBy(n => n.FrequencyValue).ToArray();
}
Console.WriteLine("-------");
AssignCode(ft[0], "");
Dictionary <char, string> encodes = new Dictionary <char, string>();
foreach (FrequencyNode val in frequencyTableList.OrderByDescending(f => f.FrequencyValue))
{
Console.WriteLine($"{val.Char} {val.FrequencyValue} {val.StringCode}");
encodes.Add(val.Char.Value, val.StringCode);
}
StringBuilder encoded = new StringBuilder();
for (int i = 0; i < text.Length; i++)
{
encoded.Append(encodes[text[i]]);
}
string encodedVal = encoded.ToString();
Console.WriteLine($"Encoded {encoded} len {encodedVal.Length / 8}");
int encodedLen = encodedVal.Length;
int currentIndex = 0;
while (currentIndex < encodedLen)
{
currentIndex = Decoding(ft[0], encodedVal, currentIndex);
}
return;