Files

.github
ci
lcsp
lib
- common
- easy
  - 1002_find_common_characters.rb
  - 1005_maximize_sum_of_array_after_k_negations.rb
  - 1009_complement_of_base_10_integer.rb
  - 100_same_tree.rb
  - 1018_binary_prefix_divisible_by_5.rb
  - 101_symmetric_tree.rb
  - 1021_remove_outermost_parentheses.rb
  - 1022_sum_of_root_to_leaf_binary_numbers.rb
  - 1025_divisor_game.rb
  - 1046_last_stone_weight.rb
  - 1047_remove_all_adjacent_duplicates_in_string.rb
  - 104_maximum_depth_of_binary_tree.rb
  - 1051_height_checker.rb
  - 1071_greatest_common_divisor_of_strings.rb
  - 1078_occurrences_after_bigram.rb
  - 1089_duplicate_zeros.rb
  - 108_convert_sorted_array_to_binary_search_tree.rb
  - 1103_distribute_candies_to_people.rb
  - 1108_defanging_an_ip_address.rb
  - 110_balanced_binary_tree.rb
  - 111_minimum_depth_of_binary_tree.rb
  - 112_path_sum.rb
  - 1137_n_th_tribonacci_number.rb
  - 1154_day_of_the_year.rb
  - 1160_find_words_that_can_be_formed_by_characters.rb
  - 1184_distance_between_bus_stops.rb
  - 1185_day_of_the_week.rb
  - 1189_maximum_number_of_balloons.rb
  - 118_pascals_triangle.rb
  - 119_pascals_triangle_ii.rb
  - 1200_minimum_absolute_difference.rb
  - 1207_unique_number_of_occurrences.rb
  - 1217_minimum_cost_to_move_chips_to_the_same_position.rb
  - 121_best_time_to_buy_and_sell_stock.rb
  - 1221_split_a_string_in_balanced_strings.rb
  - 1232_check_if_it_is_a_straight_line.rb
  - 1252_cells_with_odd_values_in_a_matrix.rb
  - 125_valid_palindrome.rb
  - 1266_minimum_time_visiting_all_points.rb
  - 1275_find_winner_on_a_tic_tac_toe_game.rb
  - 1281_subtract_the_product_and_sum_of_digits_of_an_integer.rb
  - 1287_element_appearing_more_than_25_in_sorted_array.rb
  - 1290_convert_binary_number_in_a_linked_list_to_integer.rb
  - 1295_find_numbers_with_even_number_of_digits.rb
  - 1299_replace_elements_with_greatest_element_on_right_side.rb
  - 1304_find_n_unique_integers_sum_up_to_zero.rb
  - 1309_decrypt_string_from_alphabet_to_integer_mapping.rb
  - 1313_decompress_run_length_encoded_list.rb
  - 1317_convert_integer_to_the_sum_of_two_no_zero_integers.rb
  - 1323_maximum_69_number.rb
  - 1332_remove_palindromic_subsequences.rb
  - 1337_the_k_weakest_rows_in_a_matrix.rb
  - 1342_number_of_steps_to_reduce_a_number_to_zero.rb
  - 1346_check_if_n_and_its_double_exist.rb
  - 1351_count_negative_numbers_in_a_sorted_matrix.rb
  - 1356_sort_integers_by_the_number_of_1_bits.rb
  - 1360_number_of_days_between_two_dates.rb
  - 1365_how_many_numbers_are_smaller_than_the_current_number.rb
  - 136_single_number.rb
  - 1370_increasing_decreasing_string.rb
  - 1374_generate_a_string_with_characters_that_have_odd_counts.rb
  - 1385_find_the_distance_value_between_two_arrays.rb
  - 1389_create_target_array_in_the_given_order.rb
  - 1399_count_largest_group.rb
  - 13_roman_to_integer.rb
  - 1403_minimum_subsequence_in_non_increasing_order.rb
  - 1408_string_matching_in_an_array.rb
  - 1413_minimum_value_to_get_positive_step_by_step_sum.rb
  - 1417_reformat_the_string.rb
  - 141_linked_list_cycle.rb
  - 1422_maximum_score_after_splitting_a_string.rb
  - 1431_kids_with_the_greatest_number_of_candies.rb
  - 1436_destination_city.rb
  - 1437_check_if_all_1s_are_at_least_length_k_places_away.rb
  - 1446_consecutive_characters.rb
  - 144_binary_tree_preorder_traversal.rb
  - 1450_number_of_students_doing_homework_at_a_given_time.rb
  - 1455_check_if_a_word_occurs_as_a_prefix_of_any_word_in_a_sentence.rb
  - 145_binary_tree_postorder_traversal.rb
  - 1460_make_two_arrays_equal_by_reversing_subarrays.rb
  - 1464_maximum_product_of_two_elements_in_an_array.rb
  - 1470_shuffle_the_array.rb
  - 1475_final_prices_with_a_special_discount_in_a_shop.rb
  - 1480_running_sum_of_1d_array.rb
  - 1486_xor_operation_in_an_array.rb
  - 1491_average_salary_excluding_the_minimum_and_maximum_salary.rb
  - 1496_path_crossing.rb
  - 14_longest_common_prefix.rb
  - 1502_can_make_arithmetic_progression_from_sequence.rb
  - 1507_reformat_date.rb
  - 1512_number_of_good_pairs.rb
  - 1518_water_bottles.rb
  - 1523_count_odd_numbers_in_an_interval_range.rb
  - 1528_shuffle_string.rb
  - 1534_count_good_triplets.rb
  - 1539_kth_missing_positive_number.rb
  - 1544_make_the_string_great.rb
  - 1550_three_consecutive_odds.rb
  - 1556_thousand_separator.rb
  - 1566_detect_pattern_of_length_m_repeated_k_or_more_times.rb
  - 1572_matrix_diagonal_sum.rb
  - 1576_replace_all_s_to_avoid_consecutive_repeating_characters.rb
  - 1582_special_positions_in_a_binary_matrix.rb
  - 1588_sum_of_all_odd_length_subarrays.rb
  - 1592_rearrange_spaces_between_words.rb
  - 1598_crawler_log_folder.rb
  - 1603_design_parking_system.rb
  - 1608_special_array_with_x_elements_greater_than_or_equal_x.rb
  - 160_intersection_of_two_linked_lists.rb
  - 1614_maximum_nesting_depth_of_the_parentheses.rb
  - 1619_mean_of_array_after_removing_some_elements.rb
  - 1624_largest_substring_between_two_equal_characters.rb
  - 1629_slowest_key.rb
  - 1636_sort_array_by_increasing_frequency.rb
  - 1646_get_maximum_in_generated_array.rb
  - 1652_defuse_the_bomb.rb
  - 1662_check_if_two_string_arrays_are_equivalent.rb
  - 1668_maximum_repeating_substring.rb
  - 1672_richest_customer_wealth.rb
  - 1678_goal_parser_interpretation.rb
  - 1684_count_the_number_of_consistent_strings.rb
  - 1688_count_of_matches_in_tournament.rb
  - 168_excel_sheet_column_title.rb
  - 1694_reformat_phone_number.rb
  - 169_majority_element.rb
  - 1700_number_of_students_unable_to_eat_lunch.rb
  - 1704_determine_if_string_halves_are_alike.rb
  - 1710_maximum_units_on_a_truck.rb
  - 1716_calculate_money_in_leetcode_bank.rb
  - 171_excel_sheet_column_number.rb
  - 1720_decode_xored_array.rb
  - 1725_number_of_rectangles_that_can_form_the_largest_square.rb
  - 1732_find_the_highest_altitude.rb
  - 1736_latest_time_by_replacing_hidden_digits.rb
  - 1748_sum_of_unique_elements.rb
  - 1752_check_if_array_is_sorted_and_rotated.rb
  - 1768_merge_strings_alternately.rb
  - 1773_count_items_matching_a_rule.rb
  - 1779_find_nearest_point_that_has_the_same_x_or_y_coordinate.rb
  - 1784_check_if_binary_string_has_at_most_one_segment_of_ones.rb
  - 1790_check_if_one_string_swap_can_make_strings_equal.rb
  - 1791_find_center_of_star_graph.rb
  - 1796_second_largest_digit_in_a_string.rb
  - 1800_maximum_ascending_subarray_sum.rb
  - 1805_number_of_different_integers_in_a_string.rb
  - 1812_determine_color_of_a_chessboard_square.rb
  - 1816_truncate_sentence.rb
  - 1822_sign_of_the_product_of_an_array.rb
  - 1827_minimum_operations_to_make_the_array_increasing.rb
  - 1832_check_if_the_sentence_is_pangram.rb
  - 1837_sum_of_digits_in_base_k.rb
  - 1844_replace_all_digits_with_characters.rb
  - 1848_minimum_distance_to_the_target_element.rb
  - 1859_sorting_the_sentence.rb
  - 1863_sum_of_all_subset_xor_totals.rb
  - 1869_longer_contiguous_segments_of_ones_than_zeros.rb
  - 1876_substrings_of_size_three_with_distinct_characters.rb
  - 1880_check_if_word_equals_summation_of_two_words.rb
  - 1886_determine_whether_matrix_can_be_obtained_by_rotation.rb
  - 1893_check_if_all_the_integers_in_a_range_are_covered.rb
  - 1897_redistribute_characters_to_make_all_strings_equal.rb
  - 1903_largest_odd_number_in_string.rb
  - 1909_remove_one_element_to_make_the_array_strictly_increasing.rb
  - 190_reverse_bits.rb
  - 1913_maximum_product_difference_between_two_pairs.rb
  - 191_number_of_1_bits.rb
  - 1920_build_array_from_permutation.rb
  - 1925_count_square_sum_triples.rb
  - 1929_concatenation_of_array.rb
  - 1935_maximum_number_of_words_you_can_type.rb
  - 1941_check_if_all_characters_have_equal_number_of_occurrences.rb
  - 1952_three_divisors.rb
  - 1957_delete_characters_to_make_fancy_string.rb
  - 1961_check_if_string_is_a_prefix_of_array.rb
  - 1967_number_of_strings_that_appear_as_substrings_in_word.rb
  - 1971_find_if_path_exists_in_graph.rb
  - 1974_minimum_time_to_type_word_using_special_typewriter.rb
  - 1979_find_greatest_common_divisor_of_array.rb
  - 1984_minimum_difference_between_highest_and_lowest_of_k_scores.rb
  - 1991_find_the_middle_index_in_array.rb
  - 1995_count_special_quadruplets.rb
  - 1_two_sum.rb
  - 2000_reverse_prefix_of_word.rb
  - 2006_count_number_of_pairs_with_absolute_difference_k.rb
  - 2011_final_value_of_variable_after_performing_operations.rb
  - 2016_maximum_difference_between_increasing_elements.rb
  - 2022_convert_1d_array_into_2d_array.rb
  - 2027_minimum_moves_to_convert_string.rb
  - 202_happy_number.rb
  - 2032_two_out_of_three.rb
  - 2037_minimum_number_of_moves_to_seat_everyone.rb
  - 203_remove_linked_list_elements.rb
  - 2042_check_if_numbers_are_ascending_in_a_sentence.rb
  - 2047_number_of_valid_words_in_a_sentence.rb
  - 2053_kth_distinct_string_in_an_array.rb
  - 2057_smallest_index_with_equal_value.rb
  - 205_isomorphic_strings.rb
  - 2062_count_vowel_substrings_of_a_string.rb
  - 2068_check_whether_two_strings_are_almost_equivalent.rb
  - 206_reverse_linked_list.rb
  - 2073_time_needed_to_buy_tickets.rb
  - 2078_two_furthest_houses_with_different_colors.rb
  - 2085_count_common_words_with_one_occurrence.rb
  - 2089_find_target_indices_after_sorting_array.rb
  - 2094_finding_3_digit_even_numbers.rb
  - 2099_find_subsequence_of_length_k_with_the_largest_sum.rb
  - 20_valid_parentheses.rb
  - 2103_rings_and_rods.rb
  - 2108_find_first_palindromic_string_in_the_array.rb
  - 2114_maximum_number_of_words_round_in_sentences.rb
  - 2119_a_number_after_a_double_reversal.rb
  - 2124_check_if_all_as_appears_before_all_bs.rb
  - 2129_capitalize_the_title.rb
  - 2133_check_if_every_row_and_column_contains_all_numbers.rb
  - 2138_divide_a_string_into_groups_of_size_k.rb
  - 2148_count_elements_with_strictly_smaller_and_greater_elements.rb
  - 2154_keep_multiplying_found_values_by_two.rb
  - 2160_minimum_sum_of_four_digit_number_after_splitting_digits.rb
  - 2164_sort_even_and_odd_indices_independently.rb
  - 2169_count_operations_to_obtain_zero.rb
  - 2176_count_equal_and_divisible_pairs_in_an_array.rb
  - 217_contains_duplicate.rb
  - 2180_count_integers_with_even_digit_sum.rb
  - 2185_counting_words_with_a_given_prefix.rb
  - 2190_most_frequent_number_following_key_in_an_array.rb
  - 2194_cells_in_a_range_on_an_excel_sheet.rb
  - 219_contains_duplicate_ii.rb
  - 21_merge_two_sorted_lists.rb
  - 2206_divide_array_into_equal_pairs.rb
  - 2210_count_hills_and_valleys_in_an_array.rb
  - 2215_find_the_difference_of_two_arrays.rb
  - 2220_minimum_bit_flips_to_convert_number.rb
  - 2231_largest_number_after_digit_swaps_by_parity.rb
  - 2235_add_two_integers.rb
  - 2236_root_equals_sum_of_children.rb
  - 2239_find_closest_number_to_zero.rb
  - 2243_calculate_digit_sum_of_a_string.rb
  - 2248_intersection_of_multiple_arrays.rb
  - 2255_count_prefixes_of_a_given_string.rb
  - 2259_remove_digit_from_number_to_maximize_result.rb
  - 225_implement_stack_using_queues.rb
  - 2264_largest_3_same_digit_number_in_string.rb
  - 226_invert_binary_tree.rb
  - 2278_percentage_of_letter_in_string.rb
  - 2283_check_if_number_has_equal_digit_count_and_digit_value.rb
  - 2287_rearrange_characters_to_make_target_string.rb
  - 228_summary_ranges.rb
  - 2293_min_max_game.rb
  - 2299_strong_password_checker_ii.rb
  - 2303_calculate_amount_paid_in_taxes.rb
  - 2309_greatest_english_letter_in_upper_and_lower_case.rb
  - 2315_count_asterisks.rb
  - 2319_check_if_matrix_is_x_matrix.rb
  - 231_power_of_two.rb
  - 2325_decode_the_message.rb
  - 232_implement_queue_using_stacks.rb
  - 2331_evaluate_boolean_binary_tree.rb
  - 2335_minimum_amount_of_time_to_fill_cups.rb
  - 2341_maximum_number_of_pairs_in_array.rb
  - 2347_best_poker_hand.rb
  - 234_palindrome_linked_list.rb
  - 2351_first_letter_to_appear_twice.rb
  - 2357_make_array_zero_by_subtracting_equal_amounts.rb
  - 2363_merge_similar_items.rb
  - 2367_number_of_arithmetic_triplets.rb
  - 2373_largest_local_values_in_a_matrix.rb
  - 2379_minimum_recolors_to_get_k_consecutive_black_blocks.rb
  - 2383_minimum_hours_of_training_to_win_a_competition.rb
  - 2389_longest_subsequence_with_limited_sum.rb
  - 2395_find_subarrays_with_equal_sum.rb
  - 2399_check_distances_between_same_letters.rb
  - 2404_most_frequent_even_element.rb
  - 2413_smallest_even_multiple.rb
  - 2418_sort_the_people.rb
  - 2423_remove_letter_to_equalize_frequency.rb
  - 2427_number_of_common_factors.rb
  - 242_valid_anagram.rb
  - 2432_the_employee_that_worked_on_the_longest_task.rb
  - 2441_largest_positive_integer_that_exists_with_its_negative.rb
  - 2446_determine_if_two_events_have_conflict.rb
  - 2455_average_value_of_even_numbers_that_are_divisible_by_three.rb
  - 2460_apply_operations_to_an_array.rb
  - 2469_convert_the_temperature.rb
  - 2475_number_of_unequal_triplets_in_array.rb
  - 2481_minimum_cuts_to_divide_a_circle.rb
  - 2485_find_the_pivot_integer.rb
  - 2490_circular_sentence.rb
  - 2496_maximum_value_of_a_string_in_an_array.rb
  - 2500_delete_greatest_value_in_each_row.rb
  - 2506_count_pairs_of_similar_strings.rb
  - 2511_maximum_enemy_forts_that_can_be_captured.rb
  - 2515_shortest_distance_to_target_string_in_a_circular_array.rb
  - 2520_count_the_digits_that_divide_a_number.rb
  - 2525_categorize_box_according_to_criteria.rb
  - 2529_maximum_count_of_positive_integer_and_negative_integer.rb
  - 2535_difference_between_element_sum_and_digit_sum_of_an_array.rb
  - 2540_minimum_common_value.rb
  - 2544_alternating_digit_sum.rb
  - 2549_count_distinct_numbers_on_board.rb
  - 257_binary_tree_paths.rb
  - 258_add_digits.rb
  - 263_ugly_number.rb
  - 2652_sum_multiples.rb
  - 268_missing_number.rb
  - 26_remove_duplicates_from_sorted_array.rb
  - 278_first_bad_version.rb
  - 27_remove_element.rb
  - 283_move_zeroes.rb
  - 28_find_the_index_of_the_first_occurrence_in_a_string.rb
  - 290_word_pattern.rb
  - 292_nim_game.rb
  - 2951_find_the_peaks.rb
  - 2966_divide_array_into_arrays_with_max_difference.rb
  - 2974_minimum_number_game.rb
  - 303_range_sum_query_immutable.rb
  - 3046_split_the_array.rb
  - 3083_existence_of_a_substring_in_a_string_and_its_reverse.rb
  - 3090_maximum_length_substring_with_two_occurrences.rb
  - 3110_score_of_a_string.rb
  - 3131_find_the_integer_added_to_array_i.rb
  - 3136_valid_word.rb
  - 3151_special_array_i.rb
  - 3210_find_the_encrypted_string.rb
  - 326_power_of_three.rb
  - 3280_convert_date_to_binary.rb
  - 3386_button_with_longest_push_time.rb
  - 338_counting_bits.rb
  - 342_power_of_four.rb
  - 344_reverse_string.rb
  - 345_reverse_vowels_of_a_string.rb
  - 3498_reverse_degree_of_a_string.rb
  - 349_intersection_of_two_arrays.rb
  - 350_intersection_of_two_arrays_ii.rb
  - 3516_find_closest_person.rb
  - 35_search_insert_position.rb
  - 367_valid_perfect_square.rb
  - 374_guess_number_higher_or_lower.rb
  - 383_ransom_note.rb
  - 387_first_unique_character_in_a_string.rb
  - 389_find_the_difference.rb
  - 392_is_subsequence.rb
  - 404_sum_of_left_leaves.rb
  - 405_convert_a_number_to_hexadecimal.rb
  - 409_longest_palindrome.rb
  - 412_fizz_buzz.rb
  - 414_third_maximum_number.rb
  - 415_add_strings.rb
  - 434_number_of_segments_in_a_string.rb
  - 441_arranging_coins.rb
  - 448_find_all_numbers_disappeared_in_an_array.rb
  - 455_assign_cookies.rb
  - 459_repeated_substring_pattern.rb
  - 461_hamming_distance.rb
  - 463_island_perimeter.rb
  - 476_number_complement.rb
  - 482_license_key_formatting.rb
  - 485_max_consecutive_ones.rb
  - 492_construct_the_rectangle.rb
  - 496_next_greater_element_i.rb
  - 500_keyboard_row.rb
  - 501_find_mode_in_binary_search_tree.rb
  - 504_base_7.rb
  - 506_relative_ranks.rb
  - 507_perfect_number.rb
  - 509_fibonacci_number.rb
  - 520_detect_capital.rb
  - 521_longest_uncommon_subsequence_i.rb
  - 530_minimum_absolute_difference_in_bst.rb
  - 543_diameter_of_binary_tree.rb
  - 551_student_attendance_record_i.rb
  - 557_reverse_words_in_a_string_iii.rb
  - 559_maximum_depth_of_n_ary_tree.rb
  - 561_array_partition.rb
  - 563_binary_tree_tilt.rb
  - 566_reshape_the_matrix.rb
  - 572_subtree_of_another_tree.rb
  - 589_n_ary_tree_preorder_traversal.rb
  - 58_length_of_last_word.rb
  - 590_n_ary_tree_postorder_traversal.rb
  - 594_longest_harmonious_subsequence.rb
  - 599_minimum_index_sum_of_two_lists.rb
  - 617_merge_two_binary_trees.rb
  - 628_maximum_product_of_three_numbers.rb
  - 637_average_of_levels_in_binary_tree.rb
  - 643_maximum_average_subarray_i.rb
  - 645_set_mismatch.rb
  - 653_two_sum_iv_input_is_a_bst.rb
  - 657_robot_return_to_origin.rb
  - 66_plus_one.rb
  - 671_second_minimum_node_in_a_binary_tree.rb
  - 674_longest_continuous_increasing_subsequence.rb
  - 67_add_binary.rb
  - 680_valid_palindrome_ii.rb
  - 682_baseball_game.rb
  - 693_binary_number_with_alternating_bits.rb
  - 69_sqrtx.rb
  - 700_search_in_a_binary_search_tree.rb
  - 703_kth_largest_element_in_a_stream.rb
  - 704_binary_search.rb
  - 705_design_hashset.rb
  - 706_design_hashmap.rb
  - 709_to_lower_case.rb
  - 70_climbing_stairs.rb
  - 717_1_bit_and_2_bit_characters.rb
  - 724_find_pivot_index.rb
  - 728_self_dividing_numbers.rb
  - 733_flood_fill.rb
  - 744_find_smallest_letter_greater_than_target.rb
  - 746_min_cost_climbing_stairs.rb
  - 747_largest_number_at_least_twice_of_others.rb
  - 762_prime_number_of_set_bits_in_binary_representation.rb
  - 766_toeplitz_matrix.rb
  - 771_jewels_and_stones.rb
  - 783_minimum_distance_between_bst_nodes.rb
  - 796_rotate_string.rb
  - 804_unique_morse_code_words.rb
  - 806_number_of_lines_to_write_string.rb
  - 812_largest_triangle_area.rb
  - 819_most_common_word.rb
  - 821_shortest_distance_to_a_character.rb
  - 830_positions_of_large_groups.rb
  - 832_flipping_an_image.rb
  - 83_remove_duplicates_from_sorted_list.rb
  - 844_backspace_string_compare.rb
  - 859_buddy_strings.rb
  - 860_lemonade_change.rb
  - 867_transpose_matrix.rb
  - 868_binary_gap.rb
  - 872_leaf_similar_trees.rb
  - 876_middle_of_the_linked_list.rb
  - 884_uncommon_words_from_two_sentences.rb
  - 88_merge_sorted_array.rb
  - 896_monotonic_array.rb
  - 897_increasing_order_search_tree.rb
  - 905_sort_array_by_parity.rb
  - 908_smallest_range_i.rb
  - 917_reverse_only_letters.rb
  - 922_sort_array_by_parity_ii.rb
  - 925_long_pressed_name.rb
  - 929_unique_email_addresses.rb
  - 933_number_of_recent_calls.rb
  - 938_range_sum_of_bst.rb
  - 941_valid_mountain_array.rb
  - 942_di_string_match.rb
  - 944_delete_columns_to_make_sorted.rb
  - 94_binary_tree_inorder_traversal.rb
  - 953_verifying_an_alien_dictionary.rb
  - 961_n_repeated_element_in_size_2n_array.rb
  - 965_univalued_binary_tree.rb
  - 976_largest_perimeter_triangle.rb
  - 977_squares_of_a_sorted_array.rb
  - 989_add_to_array_form_of_integer.rb
  - 993_cousins_in_binary_tree.rb
  - 997_find_the_town_judge.rb
  - 9_palindrome_number.rb
- hard
- medium
test
.gitignore
.rubocop.yml
Gemfile
README.md
Rakefile
leetcode-ruby.gemspec

1791_find_center_of_star_graph.rb

2023-12-06 v. 3.6.8: added "1791. Find Center of Star Graph"

Dec 6, 2023

b3a0d1d · Dec 6, 2023