private static CharacterFrequency[] ResolveCharacterCounts(String haystack, CharacterFrequency[] characterFrequencies)
{
Int32 index = 0;
while (haystack.Length > 0)
{
// The first character in the haystack is the next character to count
Char needle = haystack[0];
// Remove the needle from the haystack
String newHaystack = haystack.Replace(needle.ToString(), "");
// Set the character to the needle
CharacterFrequency character = new CharacterFrequency()
{
Character = needle,
Frequency = haystack.Length - newHaystack.Length // Difference is the number of removed characters
};
// Push the new character class onto the array
characterFrequencies[index] = character;
// Update the haystack with the removed character haystack
haystack = newHaystack;
index++;
}
// Return all the characters
return(characterFrequencies);
}
public override Boolean Equals(Object character)
{
// Check if the character is null or is not the same type
if (character == null || !(character.GetType() == GetType()))
{
return(false);
}
// Check if the Object is this instance
if (character == this)
{
return(true);
}
// Cast the Object to the CharacterFrequency class
CharacterFrequency instance = (CharacterFrequency)character;
return(Character == instance.Character);
}
public static void Main(String[] args)
{
try
{
String inputFile;
String outputFile;
if (args.Length == 2)
{
inputFile = args[0];
outputFile = args[1];
}
else
{
Console.Write("Please provide an input file name: ");
inputFile = Console.ReadLine();
Console.Write("Please provide an output file name: ");
outputFile = Console.ReadLine();
}
StreamReader reader = new StreamReader(inputFile);
String contents = reader.ReadToEnd();
reader.Close();
CharacterFrequency[] characterFrequencies = new CharacterFrequency[NumberOfAsciiCharacters];
characterFrequencies = ResolveCharacterCounts(contents, characterFrequencies);
SetOutput(characterFrequencies, outputFile);
}
catch (Exception e)
{
Console.WriteLine(e);
}
}
private static LinkedList <CharacterFrequency> ResolveCharacterCounts(
StreamReader reader,
LinkedList <CharacterFrequency> characterFrequencies
)
{
// Keep characterFrequency classes in a hash table so retrieval is O(1)
Hashtable characterFrequencyState = new Hashtable();
Int32 value = reader.Read();
while (value != -1)
{
Char character = (Char)value;
if (!characterFrequencyState.Contains(character))
{
CharacterFrequency characterFrequency = new CharacterFrequency()
{
Character = (Char)value,
Frequency = 1
};
characterFrequencyState.Add(character, characterFrequency);
characterFrequencies.AddLast(characterFrequency);
}
else
{
CharacterFrequency characterFrequency = (CharacterFrequency)characterFrequencyState[character];
characterFrequency.Increment();
}
value = reader.Read();
}
// Return all the characters
return(characterFrequencies);
}
private static void SetOutput(CharacterFrequency[] characterFrequencies, String outputFile)
{
StreamWriter writer = new StreamWriter(outputFile);
Int32 characterFrequenciesLength = characterFrequencies.Length;
Int32 i = 0;
for (; i < characterFrequenciesLength; i++)
{
if (characterFrequencies[i] == null)
{
break;
}
CharacterFrequency characterFrequency = characterFrequencies[i];
writer.WriteLine(
$"{characterFrequency.Character}({(Int32)characterFrequency.Character})\t\t{characterFrequency.Frequency}");
}
writer.Close();
}
