Algorithm
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How to setup Java, JUnit, gradle and Intellij, for PSAlgorithm 2021. 1. 3. 20:10
How to setup Java, JUnit, gradle and Intellij, for Problem Solving This is a specialized template regarding how to setup Java, JUnit, gradle and Intellij together. Especially, it is very good for problem solving(PS) as designed to handle multiple pairs of answer/input files. In PS, answer and input files are proived a pair, to check that your code is written well to solve a problem. So, it takes..
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WAH (word-aligned hybrid), efficient bitmap index compressAlgorithm 2020. 12. 6. 17:21
WAH(word-aligned hybrid) is very efficent way to compress bitmap index. Of course we have another compression methods, but WAH compressed bitmap can be used to logcial operation without decompression, while other methods requrie decompression before we do any logical operatoin. Summary of WAH WAH compression is done in 32bit, both 31 and 30 bits are special meaning like below. 31 bit : Indicates..
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Algorithm / TreeAlgorithm 2020. 9. 13. 18:32
Binary tree https://www.cs.usfca.edu/~galles/visualization/BST.html AVL tree https://www.cs.usfca.edu/~galles/visualization/AVLtree.html Red-Black tree https://www.cs.usfca.edu/~galles/visualization/RedBlack.html B-tree https://www.geeksforgeeks.org/introduction-of-b-tree-2/ https://www.cs.usfca.edu/~galles/visualization/BTree.html B+tree https://www.cs.usfca.edu/~galles/visualization/BPlusTree...
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Bitmap index에서 WAH 사용시 장점Algorithm 2020. 9. 6. 21:28
(위키피디아에서 일부분 밝췌함) These compression methods require very little effort to compress and decompress. 이런 압축방법들(Bitmap index의 여러가지 압축방법들을 말함), 압축과 압축풀기를 매우 쉽게 할 수 있다. More importantly, bitmaps compressed with BBC, WAH, COMPAX, PLWAH, EWAH and CONCISE can directly participate in bitwise operations without decompression. 보다 중요한 점은, BBC, WAH, COMPAX, PLWAH, EWAH and CONCISE와 같은 비트맵 압축방법은 압축풀지 않고, 바로 비트..