Updated readme.

Author: javadev

README.md

@@ -47,13 +47,16 @@ implementation 'com.github.javadev:leetcode-in-java:1.9'
 | 1996 |[The Number of Weak Characters in the Game](../main/src/main/java/g1901_2000/s1996_the_number_of_weak_characters_in_the_game/)| [Java](../main/src/main/java/g1901_2000/s1996_the_number_of_weak_characters_in_the_game/Solution.java) | Medium | Array, Sorting, Greedy, Stack, Monotonic_Stack | 121 | 81.46
 | 1995 |[Count Special Quadruplets](../main/src/main/java/g1901_2000/s1995_count_special_quadruplets/)| [Java](../main/src/main/java/g1901_2000/s1995_count_special_quadruplets/Solution.java) | Easy | Array, Enumeration | 2 | 99.20
 | 1994 |[The Number of Good Subsets](../main/src/main/java/g1901_2000/s1994_the_number_of_good_subsets/)| [Java](../main/src/main/java/g1901_2000/s1994_the_number_of_good_subsets/Solution.java) | Hard | Array, Dynamic_Programming, Math, Bit_Manipulation, Bitmask | 15 | 94.29
+| 1993 |[Operations on Tree](../main/src/main/java/g1901_2000/s1993_operations_on_tree/)| [Java](../main/src/main/java/g1901_2000/s1993_operations_on_tree/LockingTree.java) | Medium | Hash_Table, Breadth_First_Search, Tree, Design | 394 | 23.03
+| 1992 |[Find All Groups of Farmland](../main/src/main/java/g1901_2000/s1992_find_all_groups_of_farmland/)| [Java](../main/src/main/java/g1901_2000/s1992_find_all_groups_of_farmland/Solution.java) | Medium | Array, Depth_First_Search, Breadth_First_Search, Matrix | 7 | 89.08
+| 1991 |[Find the Middle Index in Array](../main/src/main/java/g1901_2000/s1991_find_the_middle_index_in_array/)| [Java](../main/src/main/java/g1901_2000/s1991_find_the_middle_index_in_array/Solution.java) | Easy | Array, Prefix_Sum | 0 | 100.00
 | 1987 |[Number of Unique Good Subsequences](../main/src/main/java/g1901_2000/s1987_number_of_unique_good_subsequences/)| [Java](../main/src/main/java/g1901_2000/s1987_number_of_unique_good_subsequences/Solution.java) | Hard | String, Dynamic_Programming | 19 | 53.78
 | 1986 |[Minimum Number of Work Sessions to Finish the Tasks](../main/src/main/java/g1901_2000/s1986_minimum_number_of_work_sessions_to_finish_the_tasks/)| [Java](../main/src/main/java/g1901_2000/s1986_minimum_number_of_work_sessions_to_finish_the_tasks/Solution.java) | Medium | Array, Dynamic_Programming, Bit_Manipulation, Backtracking, Bitmask | 2 | 90.18
 | 1957 |[Delete Characters to Make Fancy String](../main/src/main/java/g1901_2000/s1957_delete_characters_to_make_fancy_string/)| [Java](../main/src/main/java/g1901_2000/s1957_delete_characters_to_make_fancy_string/Solution.java) | Easy | String | 54 | 52.94
 | 1955 |[Count Number of Special Subsequences](../main/src/main/java/g1901_2000/s1955_count_number_of_special_subsequences/)| [Java](../main/src/main/java/g1901_2000/s1955_count_number_of_special_subsequences/Solution.java) | Hard | Array, Dynamic_Programming | 22 | 80.65
 | 1954 |[Minimum Garden Perimeter to Collect Enough Apples](../main/src/main/java/g1901_2000/s1954_minimum_garden_perimeter_to_collect_enough_apples/)| [Java](../main/src/main/java/g1901_2000/s1954_minimum_garden_perimeter_to_collect_enough_apples/Solution.java) | Medium | Math, Binary_Search | 2 | 59.57
 | 1953 |[Maximum Number of Weeks for Which You Can Work](../main/src/main/java/g1901_2000/s1953_maximum_number_of_weeks_for_which_you_can_work/)| [Java](../main/src/main/java/g1901_2000/s1953_maximum_number_of_weeks_for_which_you_can_work/Solution.java) | Medium | Array, Greedy | 4 | 40.93
-| 1952 |[Three Divisors](../main/src/main/java/g1901_2000/s1952_three_divisors/)| [Java](../main/src/main/java/g1901_2000/s1952_three_divisors/Solution.java) | Easy | Math | 3 | 6.76
+| 1952 |[Three Divisors](../main/src/main/java/g1901_2000/s1952_three_divisors/)| [Java](../main/src/main/java/g1901_2000/s1952_three_divisors/Solution.java) | Easy | Math | 1 | 84.91
 | 1948 |[Delete Duplicate Folders in System](../main/src/main/java/g1901_2000/s1948_delete_duplicate_folders_in_system/)| [Java](../main/src/main/java/g1901_2000/s1948_delete_duplicate_folders_in_system/Solution.java) | Hard | Array, String, Hash_Table, Trie, Hash_Function | 92 | 97.82
 | 1947 |[Maximum Compatibility Score Sum](../main/src/main/java/g1901_2000/s1947_maximum_compatibility_score_sum/)| [Java](../main/src/main/java/g1901_2000/s1947_maximum_compatibility_score_sum/Solution.java) | Medium | Array, Dynamic_Programming, Bit_Manipulation, Backtracking, Bitmask | 2 | 95.90
 | 1946 |[Largest Number After Mutating Substring](../main/src/main/java/g1901_2000/s1946_largest_number_after_mutating_substring/)| [Java](../main/src/main/java/g1901_2000/s1946_largest_number_after_mutating_substring/Solution.java) | Medium | Array, String, Greedy | 18 | 70.91