609. Find Duplicate File in System

FindDuplicate.cs

public class Solution {
  const char Separator = ' ';
  const char StartContentCharacter = '(';
  const char EndContentCharacter = ')';
  public IList<IList<string>> FindDuplicate(string[] paths) {
    
    // [full file path, content]
    static string GetFileName(in string fileAndContent) =>
      fileAndContent[0..(fileAndContent.IndexOf(StartContentCharacter))];
    
    static string GetFileContent(in string fileAndContent)=>
      fileAndContent[(fileAndContent.IndexOf(StartContentCharacter) + 1)..fileAndContent.IndexOf(EndContentCharacter)];
    
    string[][] GetFilesAndContent(in string path){
      var s = path.Split(Separator);
      var directory = s[0];
      var filesAndContent = s[1..];
      
      var res = new List<string[]>();
      foreach(var fileAndContent in filesAndContent){
        var fileName = GetFileName(fileAndContent);
        var fileContent = GetFileContent(fileAndContent);
        var fullPath = $"{directory}/{fileName}";        
        res.Add(new string[]{ fullPath, fileContent });
      }
      
      return res.ToArray();
    }
    
    // key: file content..., List<string> full file paths,
    var duplicated = new Dictionary<string, List<string>>();
    
    foreach(var path in paths){
      var filesAndContent = GetFilesAndContent(path);
      foreach(var fileAndContent in filesAndContent){
        var fullFilePath = fileAndContent[0];
        var content = fileAndContent[1];
        if(!duplicated.ContainsKey(content))
          duplicated[content] = new();
        duplicated[content].Add(fullFilePath);
      }
    }
    var duplicatedFiles = new List<IList<string>>();
    
    foreach(var dup in duplicated.Values){
      if(dup.Count <= 1)
        continue;
      var files = new List<string>();
      foreach(var duplicatedFile in dup)
        files.Add(duplicatedFile);
      duplicatedFiles.Add(files);
    }
    
    return duplicatedFiles;
  }
}