CP

• http://aperiodic.net/phil/scala/s-99/
• https://www.youtube.com/watch?v=wvVqDkX8U4A&list=PLl0KD3g-oDOHElCF7S7q6CRGz1qG8vQkS
• https://cses.fi/book/book.pdf
• https://cp-algorithms.com/
• https://stackoverflow.com/questions/53678392/h-tree-using-recursion-python

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