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Collections are a way for you to organize kata so that you can create your own training routines. Every collection you create is public and automatically sharable with other warriors. After you have added a few kata to a collection you and others can train on the kata contained within the collection.
Get started now by creating a new collection.
well, my solution is faster than O(2n) i think. Not so elegant, but have only one filter.
These belongs to elementary algebra (which should be what have been taught in schools?). They're instantly recognizable once you have enough experience on basic maths.
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