nim / Sprague Grunge Theorem Stirling / Eulerian numbers applications Burnside Lemma fft bipartite matching / Halls Marriage theorem Dilworths therorem Königs Theoren sqrt decomp (mo's algo) floyd warshall negative cycle detection lazy segment tree HLD with range updates Test Min cost flow Test Minimum-Cost Arborescence Test Bigint division/module Division Remainder lazy, persistent, pointer-based segment tree linear sieve rework .vimrc biconnected components