帮我用C#语言写一段不同字符串中出现的高频词的程序。

好的，您可以参考以下代码：

using System;
using System.Collections.Generic;
using System.Linq;

namespace HighFrequencyWords
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] strings = { "hello world", "world is beautiful", "hello beautiful world" };
            Dictionary<string, int> wordCount = new Dictionary<string, int>();

            // 统计每个单词的出现次数
            foreach (string str in strings)
            {
                string[] words = str.Split(' ');
                foreach (string word in words)
                {
                    if (wordCount.ContainsKey(word))
                    {
                        wordCount[word]++;
                    }
                    else
                    {
                        wordCount[word] = 1;
                    }
                }
            }

            // 找出出现次数最多的单词
            int maxCount = wordCount.Values.Max();
            var mostFrequentWords = wordCount.Where(x => x.Value == maxCount).Select(x => x.Key);

            // 输出结果
            Console.WriteLine("出现次数最多的单词为：");
            foreach (string word in mostFrequentWords)
            {
                Console.WriteLine(word);
            }
        }
    }
}

这段代码会在输入的字符串中找出出现次数最多的单词并输出。您可以根据需要对代码进行修改和优化。