Phase 1 / strings, palindrome, prefix_suffix
Phase 1 / graph, dfs, coloring
Phase 1 / number_theory, sliding_window
Phase 1 / dp, lex_order
Phase 1 / mst, parity, union_find
Phase 1 / sliding_window, parity
Phase 1 / prefix_xor, greedy
Phase 6 / combined-techniques
Phase 5 / advanced-dp
Phase 4 / segment-tree
Phase 3 / graph-shortest-path
Phase 2 / binary-search-answer