* feat: add 2-3-4 tree implment
* updating DIRECTORY.md
* docs: fix format issue of tab&space
* fix: fix code format issues
* fix: convert printf() to std::cout
* fix: fix some clang-tidy warnings
* fix: fix clang-tidy warnings of memory owning
* fix: remove use of std::make_unique which is not support by c++11
* docs: improve documents
* fix: replace fprint with ofstream, and improve docs
* docs: improve docs for including header file
* docs: improve file doces
* fix: convert item type to int64_t, convert node item count type to int8_t
* refactor: Apply suggestions from code review
Add namespaces
Co-authored-by: David Leal <halfpacho@gmail.com>
* docs: remove obsolete comments
Co-authored-by: liuhuan <liuhuan@ainirobot.com>
Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>
Co-authored-by: David Leal <halfpacho@gmail.com>
