Chapter 19 Variant Gallery: capture the repo's cool duplicate implementations — TSP top-down functional DP, LRU linked-list family, Coin Change BFS, N-Queens set-based, short-code gallery, Eulerian trio (circuit/arrangement/de Bruijn), functional-style gallery, Word Ladder II forward BFS, LFU trio, TreeSet sliding median · arpanpathak/AdvancedAlgorithmPatterns@7f1b4e7