Almost-linear-time exact matching and prescribed-degree factors in general graphs

Gives a randomized algorithm finding an exact maximum-cardinality matching in any simple undirected graph in $(n+m)^{1+o(1)}$ word time, with success probability at least 2/3. The time bound holds on every computation path. The same guarantees apply to finding a spanning subgraph with prescribed admissible vertex degrees, or deciding that none exists.