Rework WCC implementation #202
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Fixes #200
The old WCC implementation did not work properly in parallel, leading in some cases to a segmentation fault because memory was incorrectly written to and read from (#200).
We rework the implementation of WCC in this PR to fix this issue and also improve the performance. See https://github.com/yoba7/connected-components/tree/main for details on the current implementation.
The algorithm works single-threaded (similar to our PageRank implementation) to avoid race conditions when two different threads would explore the same connected component at the same time and potentially overwrite each other. Perhaps a future implementation could look at making this multithreaded.
On a graph of 3.5M edges, it takes approx. 1.25 seconds, whereas networkX takes 7.5s (excluding load times)