Search Engine

Search engine is C++ console application that enables users to add documents of words to database and perform queries. The API of SearchServer is following:

class SearchServer {
public:
  SearchServer() = default;
  explicit SearchServer(istream& document_input);

  void UpdateDocumentBase(istream& document_input);
  void AddQueriesStream(istream& query_input, ostream& search_results_output);
};

AddQueriesStream method

It accepts input stream of search queries query_input, and output stream of search results search_results_output to write to.

The search result is set of maximum 5 most relevant documents. The document relevancy is calculated as sum of hit counts of each query words in the document. Suppose, we need to search query the best capital in the database that has three documents:

• "london is the capital of great britain"
• "moscow is the capital of the russian federation"
• *"paris is the capital of france"

Then relevancy metrics of those documents would be:

• "london is the capital of great britain" - 2 ("the" word appeared 1 time, "best" - 0, "capital" - 1)
• "moscow is the capital of the russian federation" - 3 ("the" word appeared 2 times, "best" — 0, "capital" — 1)
• *"paris is the capital of france" - 2 ("the" — 1, "best" — 0, "capital" — 1)

Thus, the "moscow is the capital of the russian federation" is the most relevant document to abovementioned search query.

UpdateDocumentBase method

This method replaces the content of the database with a new set of documents. For example, the following code:

const string doc1 = "london is the capital of great britain";
const string doc2 = "moscow is the capital of the russian federation";
istringstream doc_input1(doc1 + '\n' + doc2);
SearchServer srv(doc_input1);

const string query = "the capital";
istringstream query_input1(query);
srv.AddQueriesStream(query_input1, cout);

istringstream doc_input2(doc2 + '\n' + doc1);
srv.UpdateDocumentBase(doc_input2);
istringstream query_input2(query);
srv.AddQueriesStream(query_input2, cout);

Should return:

the capital: {docid: 1, hitcount: 3} {docid: 0, hitcount: 2}
the capital: {docid: 0, hitcount: 3} {docid: 1, hitcount: 2}

To get started:

• Clone this project
• Add this build task if you are using VS code:

{
	"version": "2.0.0",
	"tasks": [
		{
			"type": "cppbuild",
			"label": "C/C++: clang++ build directory",
			"command": "/usr/bin/clang++",
			"args": [
				"-std=c++2a",
				"-stdlib=libc++",
				"-g",
				"${fileDirname}/*.cpp",
				"-o",
				"${fileDirname}/${fileBasenameNoExtension}"
			],
			"options": {
				"cwd": "${workspaceFolder}"
			},
			"problemMatcher": [
				"$gcc"
			],
			"group": {
				"kind": "build",
				"isDefault": true
			},
			"detail": "compiler: /usr/bin/clang++"
		}
	]
}

• Run "C/C++: clang++ build directory" run task to compile
• Run ./main from command line
• Create your own test using TestFunctionality() template