Phase 6 / string/hash
Phase 6 / greedy/array
Phase 6 / graph/grid/shortest-path
Phase 5 / dp, coloring, min cost
Phase 4 / dp, parity, combinatorics
Phase 6 / tree, lca, path, color counting
Phase 5 / heap, lex order, merge
Phase 4 / bfs, array, shortest path
Phase 6 / tree, dfs, component, diameter
Phase 4 / prefix sum, set, sliding window
Phase 6 / dsu, offline, reverse delete
Phase 5 / modulo, dp, multiset