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A compactly encoded dataset containing all 30,368 unlabeled connected 3-regular graphs on 32 vertices with girth at least 7
| Vertex 1 | reads 2, 3, 4 | Edge: 1-2, Edge: 1-3, Edge: 1-4 |
| Vertex 2 | reads 3, 4 | Edge: 2-3, Edge: 2-4 |
| Vertex 3 | read 4 | Edge: 3-4 |
| Vertex 4 | read nothing | No more entries |
The the two adjacency lists are ( 2 3 4 5 3 4 5 6 7 6 7 6 7 7 ) and (2 3 4 5 3 4 6 5 7 6 7 6 7 7). This compression is very effective when consecutive graphs share long common prefixes, which happens frequently in the systematic generation process.The following steps demonstrate how to convert the list into graphs. Start with the base cubic graph:
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Convert the data into adjacency lists:
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Choose several random cubic graphs from our database:
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The graphs in the database are 3-regular. For instances:
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All vertices have degree three:
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The girths or the lengths of shortest cycle in the graphs are at least seven:
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The graphs are pair-wisely non-isomorphic or structurally inequivalent:
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The graphs may have different centrality:
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The cubic graphs may share large isomorphic subgraphs:
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A subgraph of the second entry in the list above:
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The subgraph contains 100% vertices and 95.8% edges of the graphs above:
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Show that the graph is indeed the subgraph of both entries above:
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Highlight the maximal isomorphic sub-structure of both entries with dashed lines:
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Shenghui Yang, "All Unlabeled Cubic Graphs of Order 32 with Girth at Least 7" from the Wolfram Data Repository (2026)