Red-black tree node insertion and deletion: - [Insertion](https://www.youtube.com/watch?v=UaLIHuR1t8Q&list=PLLXdhg_r2hKA7DPDsunoDZ-Z769jWn4R8&index=69) - [Deletion](https://www.youtube.com/watch?v=CTvfzU_uNKE&list=PLLXdhg_r2hKA7DPDsunoDZ-Z769jWn4R8&index=68)