C#给这个倒排索引添加一个输出方法

Question

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

namespace InvertedIndex
{
class Term
{
public string word;
public int doc_freq;
}
class invertedIndex
{
Dictionary> index = new Dictionary>();
Dictionary mapping = new Dictionary();

    public invertedIndex(string path)
    {
        init(path);
    }
    void init(string path)
    {
        string[] files = Directory.GetFiles(path);
        foreach (string file in files)
        {
            int doc_id = mapping.Count + 1;
            mapping.Add(doc_id, file);
            StreamReader sr = new StreamReader(file);
            string content = sr.ReadToEnd();
            string[] words = content.Split(new char[] { ' ', ',', ';', '.', '!' }, StringSplitOptions.RemoveEmptyEntries);
            foreach (string word in words)
            {
                Term term = index.Keys.FirstOrDefault(m => m.word == word);
                if (term == null)
                {
                    term = new Term();
                    term.word = word;
                    term.doc_freq = 1;

                    List<int> posting = new List<int>();
                    posting.Add(doc_id);

                    index.Add(term, posting);
                }
                else
                {
                    List<int> posting = index[term];
                    if (!posting.Contains(doc_id))
                    {
                        posting.Add(doc_id);
                        index.Remove(term);
                        term.doc_freq++;
                        index.Add(term, posting);
                    }
                }
            }
        }
    }
    public void output()
    {

    }
}

}

Answer 1

foreach (var item in index.Keys)
{
Console.WriteLine(item + "," + index[item]);
}