Question

我和我的同事尝试建立一个单词计数器，以从某个路径查找5个最常见的单词并将其输出到控制台中。到目前为止，我们仅设法编写了一个代码来搜索输入的单词及其出现的次数。

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace wordcounter_2._0
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Bitte geben sie eine Keywort ein.");
            string patternWord = Console.ReadLine();
            Console.WriteLine("Bitte geben sie einen Pfad ein.");
            string Pfad = Console.ReadLine();
            try
            {
                StreamReader MyReader = new StreamReader(Pfad);
                string text = MyReader.ReadToEnd();
            }
            catch
            {
                Console.WriteLine("Bitte geben sie einen gültigen Pfad ein.");
            }
            string[] inputSentence = Console.ReadLine().Split();
            int count = 0;
            string pattern = @"(?:\b\w+\ \s|\S)*" + patternWord + @"(?:\b\w+\b\ \s|\S)?";
            Regex rx = new Regex(pattern, RegexOptions.IgnoreCase);
            for (int i = 0; i < inputSentence.Length; i++)
            {
                var mc = rx.Matches(inputSentence[i]);
                foreach (Match m in mc)
                {
                    count++;
                }
            }
            Console.WriteLine("Das Wort " + patternWord + " kommt " + "{0}", count + " mal vor.");
            Console.ReadLine();
        }
    }
}

Answer 1

class Program
    {
        static void Main(string[] args)
        {
            string words = "I felt happy because I saw the others were happy and because I knew I should feel happy, but I wasn’t really happy.";
            string[] splitWords = words.Split(new string[] { " " }, StringSplitOptions.RemoveEmptyEntries);
            var commonWords = splitWords.ToList().GroupBy(e => e).Select(g => new { Value = g.Key, Count = g.Count() }).OrderByDescending(e => e.Count).Take(5);
            foreach (var x in commonWords)
            {
                Console.WriteLine("Value: " + x.Value); // These are the 5 most used words, if you want you can include + " Count: " + x.Count to see count
            }
            Console.ReadLine();
        }
    }

这将解决您的目的

Answer 2

这里是基于正则表达式的解决方案

string regWords = "I felt happy because I saw the others were happy and because I knew I should feel happy, but I wasn’t really happy.";
var regMatches = Regex.Matches(regWords, "\\b(?<word>[^\\s]+?)\\b");
var regCommonWords = regMatches.GroupBy(x => x.Groups["word"].Value).OrderByDescending(x => x.Count()).Take(5).Select(x => x.Key);
foreach (var x in regCommonWords)
        Console.WriteLine("Value: " + x);

要了解正则表达式的功能，请看以下内容：

https://regex101.com/r/OTBN5V/1

请牢记，通过拆分字符串，此解决方案比非正则表达式解决方案要慢。

https://dotnetfiddle.net/E4GDrj

使用vinothvs答案比较速度差异。

警告：

我的解决方案没有将“不是”视为一个单词，而是将“ wasn”和“ t”视为单独的单词，找不到解决此问题的令人满意的方法。

查找字符串中最常见的5个单词

2 个答案: