Phase 3 / permutation, cycles, greedy
Phase 2 / greedy, strings
Phase 4 / greedy/flipping/min_cost
Phase 4 / greedy/matching/abs_sum
Phase 5 / binary_search/greedy/partition
Phase 4 / greedy/fixed_points/segment_cover
Phase 5 / trees/pruning/path_max
Phase 5 / greedy/xor/array_manipulation
Phase 5 / number theory, primes, greedy
Phase 5 / greedy, intervals
Phase 5 / graphs, degree, greedy
Phase 5 / strings, greedy, sets