Phase 5 / dp, bitwise, LIS
Phase 5 / dp, grid, parity
Phase 6 / mo's algorithm, frequency, range query
Phase 4 / greedy, math, optimization
Phase 6 / graph decomposition, coloring, matching
Phase 4 / stack, segment tree, deque
Phase 5 / string, array, hashing, two pointers
Phase 6 / tree, path query, exclusion subtree
Phase 5 / 2D prefix sums, sliding window
Phase 6 / graphs, shortest paths, parity
Phase 6 / dp, sliding window, optimization
Phase 4 / sliding_window, frequency_map