我有一个类似的问题，但是对于单词出现！所以，我希望这会有所帮助。我使用SortedDictionary了一个二叉搜索树
/* Application counts the number of occurrences of each word in a string
and stores them in a generic sorted dictionary. */
using System;
using System.Text.RegularExpressions;
using System.Collections.Generic;
public class SortedDictionaryTest
{
public static void Main( string[] args )
{
// create sorted dictionary
SortedDictionary< string, int > dictionary = CollectWords();
// display sorted dictionary content
DisplayDictionary( dictionary );
}
// create sorted dictionary
private static SortedDictionary< string, int > CollectWords()
{
// create a new sorted dictionary
SortedDictionary< string, int > dictionary =
new SortedDictionary< string, int >();
Console.WriteLine( "Enter a string: " ); // prompt for user input
string input = Console.ReadLine();
// split input text into tokens
string[] words = Regex.Split( input, @"\s+" );
// processing input words
foreach ( var word in words )
{
string wordKey = word.ToLower(); // get word in lowercase
// if the dictionary contains the word
if ( dictionary.ContainsKey( wordKey ) )
{
++dictionary[ wordKey ];
}
else
// add new word with a count of 1 to the dictionary
dictionary.Add( wordKey, 1 );
}
return dictionary;
}
// display dictionary content
private static void DisplayDictionary< K, V >(
SortedDictionary< K, V > dictionary )
{
Console.WriteLine( "\nSorted dictionary contains:\n{0,-12}{1,-12}",
"Key:", "Value:" );
/* generate output for each key in the sorted dictionary
by iterating through the Keys property with a foreach statement*/
foreach ( K key in dictionary.Keys )
Console.WriteLine( "{0,- 12}{1,-12}", key, dictionary[ key ] );
Console.WriteLine( "\nsize: {0}", dictionary.Count );
}
}