Given a list of graph edges:\n`a->b, a->c, b->d, c->d`\n\nMerge all nodes that have share all the same edges going in and share all the same edges going out. So in the above example, we should merge `b` and `c` into the node `bc` because they both share `a` as an in-edge and share `d` as an out-edge.\n\nOutput should be like:\n`a->bc, bc->d`\n\nAnother example:\n`a->b, a->c, b->d, c->d, b->e, c->e`\nreturns\n`a->bc, bc->de`\n\nSo first I put everything into an adjacency list. Then I reversed the edges and created an adjacency list out of that to create a graph of in-edges. Then for each node in the graph, I check its in-edges and the out-edges against the in-edges and out-edges of every other node, and merge into a new node if they are equal.\n\nHowever, this is n^2 run time, and I only managed to merge `bc->d` but not `a->bc`.\n\nI feel that went poorly. How would I do this?

Given a list of graph edges:\na->b, a->c, b->d, c->d\n\nMerge all nodes that have share all the same edges going in and share all the same edges going out. So i