* style: enabled InnerAssignment in checkstyle
* Refactor code formatting in KnapsackMemoization.java and UnionFind.java
* style: remove redundant blank line
* style: mark `includeCurrentItem` and `excludeCurrentItem` as `final`
* style: remove `KnapsackMemoization` from `pmd-exclude.properties`
* style: use `final`
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Co-authored-by: Piotr Idzik <65706193+vil02@users.noreply.github.com>