001 001.Two_Sum Python Java C++       Notes 002 002.Add_Two_Numbers Python Java C++       Notes 003 003.Longest_Substring_Without_Repeat... Python Java C++       Notes 004 004.Median_of_Two_Sorted_Arrays Python Java C++       Notes 005 005.Longest_Palindromic_Substring Python Java C++       Notes 006 006.ZigZag_Conversion Python Java C++       Notes 007 007.Reverse_Integer Python Java C++       Notes 008 008.String_to_Integer Python Java C++       Notes 009 009.Palindrome_Number Python Java C++       Notes 010 010.Regular_Expression_Matching Python Java C++       Notes 011 011.Container_With_Most_Water Python Java C++       Notes 012 012.Integer_to_Roman Python Java C++       Notes 013 013.Roman_to_Integer Python Java C++       Notes 014 014.Longest_Common_Prefix Python Java C++       Notes 015 015.3Sum Python Java C++       Notes 016 016.3Sum_Closest Python Java C++       Notes 017 017.Letter_Combinations_of_a_Phone_Number Python Java C++       Notes 018 018.4Sum Python Java C++       Notes 019 019.Remove_Nth_Node_From_End_of_List    Python C++       Notes 020 020.Valid_Parentheses Python Java C++       Notes 021 021.Merge_Two_Sorted_Lists    Python C++       Notes 022 022.Generate_Parentheses Python Java C++       Notes 023 023.Merge_k_Sorted_Lists Python Java C++       Notes 024 024.Swap_Nodes_in_Pairs    Python C++       Notes 025 025.Reverse_Nodes_in_k-Group      Java C++       Notes 026 026.Remove_Duplicates_from_Sorted_Array           C++       Notes 027 027.Remove_Element           C++       Notes 028 028.Implement_strStr()    Python C++       Notes 029 029.Divide_Two_Integers    Python C++       Notes 030 030.Substring_with_Concatenation_of_...      Java C++       Notes 031 031.Next_Permutation    Python C++       Notes 032 032.Longest_Valid_Parentheses           C++       Notes 033 033.Search_in_Rotated_Sorted_Array           C++       Notes 034 034.Search_for_a_Range      Java C++       Notes 035 035.Search_Insert_Position           C++       Notes 036 036.Valid_Sudoku           C++       Notes 037 037.Sudoku_Solver           C++       Notes 038 038.Count_and_Say    Python C++       Notes 039 039.Combination_Sum           C++       Notes 040 040.Combination_Sum_II           C++       Notes 041 041.First_Missing_Positive           C++ Coming soon 042 042.Trapping_Rain_Water           C++ Coming soon 043 043.Multiply_Strings           C++ Coming soon 044 044.Wildcard_Matching           C++ Coming soon 045 045.Jump_Game_II           C++ Coming soon 046 046.Permutations           C++ Coming soon 047 047.Permutations_II           C++ Coming soon 048 048.Rotate_Image           C++ Coming soon 049 049.Anagrams           C++ Coming soon 050 050.Pow(x,_n)           C++ Coming soon 051 051.N-Queens Python Java C++ Coming soon 052 052.N-Queens_II Python Java C++ Coming soon 053 053.Maximum_Subarray           C++ Coming soon 054 054.Spiral_Matrix           C++ Coming soon 055 055.Jump_Game           C++ Coming soon 056 056.Merge_Intervals           C++ Coming soon 057 057.Insert_Interval           C++ Coming soon 058 058.Length_of_Last_Word           C++ Coming soon 059 059.Spiral_Matrix_II           C++ Coming soon 060 060.Permutation_Sequence           C++ Coming soon 061 061.Rotate_List           C++ Coming soon 062 062.Unique_Paths           C++ Coming soon 063 063.Unique_Paths_II           C++ Coming soon 064 064.Minimum_Path_Sum           C++ Coming soon 065 065.Valid_Number Python Java C++ Coming soon 066 066.Plus_One           C++ Coming soon 067 067.Add_Binary           C++ Coming soon 068 068.Text_Justification Python Java C++       Notes 069 069.Sqrt(x) Python Java C++ Coming soon 070 070.Climbing_Stairs           C++ Coming soon 071 071.Simplify_Path Python Java C++ Coming soon 072 072.Edit_Distance           C++ Coming soon 073 073.Set_Matrix_Zeroes           C++ Coming soon 074 074.Search_a_2D_Matrix           C++ Coming soon 075 075.Sort_Colors           C++ Coming soon 076 076.Minimum_Window_Substring           C++       Notes 077 077.Combinations           C++ Coming soon 078 078.Subsets Python Java C++ Coming soon 079 079.Word_Search           C++ Coming soon 080 080.Remove_Duplicates_from_Sorted_Array_II           C++ Coming soon 081 081.Search_in_Rotated_Sorted_Array_II           C++ Coming soon 082 082.Remove_Duplicates_from_Sorted_List_II           C++ Coming soon 083 083.Remove_Duplicates_from_Sorted_List           C++ Coming soon 084 084.Largest_Rectangle_in_Histogram      Java C++       Notes 085 085.Maximal_Rectangle      Java C++       Notes 086 086.Partition_List Python Java C++ Coming soon 087 087.Scramble_String Python Java C++       Notes 088 088.Merge_Sorted_Array           C++ Coming soon 089 089.Gray_Code Python Java C++ Coming soon 090 090.Subsets_II Python Java C++ Coming soon 091 091.Decode_Ways Python Java C++ Coming soon 092 092.Reverse_Linked_List_II           C++ Coming soon 093 093.Restore_IP_Addresses Python Java C++       Notes 094 094.Binary_Tree_Inorder_Traversal           C++ Coming soon 095 095.Unique_Binary_Search_Trees           C++       Notes 096 096.Unique_Binary_Search_Trees_II           C++       Notes 097 097.Interleaving_String      Java C++       Notes 098 098.Validate_Binary_Search_Tree Python Java C++       Notes 099 099.Recover_Binary_Search_Tree    Python C++       Notes 100 100.Same_Tree           C++ Coming soon 101 101.Symmetric_Tree           C++ Coming soon 102 102.Binary_Tree_Level_Order_Traversal    Python C++       Notes 103 103.Binary_Tree_Zigzag_Level_Order_Traversal    Python C++       Notes 104 104.Maximum_Depth_of_Binary_Tree           C++ Coming soon 105 105.Construct_Binary_Tree_from_Preor...           C++       Notes 106 106.Construct_Binary_Tree_from_Inord...           C++       Notes 107 107.Binary_Tree_Level_Order_Traversal_II    Python C++       Notes 108 108.Convert_Sorted_Array_to_Binary_S...           C++       Notes 109 109.Convert_Sorted_List_to_Binary_Se...    Python C++       Notes 110 110.Balanced_Binary_Tree           C++ Coming soon 111 111.Minimum_Depth_of_Binary_Tree           C++ Coming soon 112 112.Path_Sum           C++ Coming soon 113 113.Path_Sum_II Python Java C++ Coming soon 114 114.Flatten_Binary_Tree_to_Linked_List      Java C++       Notes 115 115.Distinct_Subsequences    Python C++       Notes 116 116.Populating_Next_Right_Pointers_i... Python Java C++ Coming soon 117 117.Populating_Next_Right_Pointers_i... Python Java C++ Coming soon 118 118.Pascal's_Triangle           C++ Coming soon 119 119.Pascal's_Triangle_II           C++ Coming soon 120 120.Triangle Python Java C++ Coming soon 121 121.Best_Time_to_Buy_and_Sell_Stock    Python C++       Notes 122 122.Best_Time_to_Buy_and_Sell_Stock_II    Python C++       Notes 123 123.Best_Time_to_Buy_and_Sell_Stock_III    Python C++       Notes 124 124.Binary_Tree_Maximum_Path_Sum    Python C++       Notes 125 125.Valid_Palindrome           C++ Coming soon 126 126.Word_Ladder    Python C++       Notes 126 126.Word_Ladder_II               Coming soon 127 127.Word_Ladder               Coming soon 128 128.Longest_Consecutive_Sequence               Coming soon 129 129.Sum_Root_to_Leaf_Numbers           C++ Coming soon 130 130.Surrounded_Regions           C++       Notes 131 131.Palindrome_Partitioning    Python C++       Notes 132 132.Palindrome_Partitioning_II      Java C++       Notes 133 133.Clone_Graph           C++ Coming soon 134 134.Gas_Station           C++       Notes 135 135.Candy               Coming soon 136 136.Single_Number           C++       Notes 137 137.Single_Number_II           C++ Coming soon 138 138.Copy_List_with_Random_Pointer Python Java C++       Notes 139 139.Word_Break    Python C++       Notes 140 140.Word_Break_II               Coming soon 141 141.Linked_List_Cycle           C++ Coming soon 142 142.Linked_List_Cycle_II               Coming soon 143 143.Reorder_List           C++ Coming soon 144 144.Binary_Tree_Preorder_Traversal           C++ Coming soon 145 145.Binary_Tree_Postorder_Traversal           C++ Coming soon 146 146.LRU_Cache    Python C++       Notes 147 147.Insertion_Sort_List           C++ Coming soon 148 148.Sort_List           C++       Notes 149 149.Max_Points_on_a_Line               Coming soon 150 150.Evaluate_Reverse_Polish_Notation Python Java C++       Notes 151 151.Reverse_Words_in_a_String Python Java C++       Notes 152 152.Maximum_Product_Subarray           C++ Coming soon 153 153.Find_Minimum_in_Rotated_Sorted_Array           C++       Notes 154 154.Find_Minimum_in_Rotated_Sorted_Array_II    Python C++       Notes 155 155.Min_Stack           C++       Notes 156 156.Binary_Tree_Upside_Down $        Not Buy     Not Buy 157 157.Read_N_Characters_Given_Read4 $        Not Buy     Not Buy 158 158.Read_N_Characters_Given_Read4_II... $        Not Buy     Not Buy 159 159.Longest_Substring_with_At_Most_T... $        Not Buy     Not Buy 160 160.Intersection_of_Two_Linked_Lists           C++ Coming soon 161 161.One_Edit_Distance $        Not Buy     Not Buy 162 162.Find_Peak_Element Python Java C++ Coming soon 163 163.Missing_Ranges $        Not Buy     Not Buy 164 164.Maximum_Gap           C++       Notes 165 165.Compare_Version_Numbers           C++ Coming soon 166 166.Fraction_to_Recurring_Decimal           C++       Notes 167 167.Two_Sum_II_-_Input_array_is_sorted $        Not Buy     Not Buy 168 168.Excel_Sheet_Column_Title Python Java C++ Coming soon 169 169.Majority_Element Python Java C++ Coming soon 170 170.Two_Sum_III_-_Data_structure_design $        Not Buy     Not Buy 171 171.Excel_Sheet_Column_Number Python Java C++ Coming soon 172 172.Factorial_Trailing_Zeroes Python Java C++ Coming soon 173 173.Binary_Search_Tree_Iterator    Python C++       Notes 174 174.Dungeon_Game               Coming soon 175 175.Combine_Two_Tables           Sql Coming soon 176 176.Second_Highest_Salary           Sql Coming soon 177 177.Nth_Highest_Salary           Sql       Notes 178 178.Rank_Scores           Sql       Notes 179 179.Largest_Number Python Java C++ Coming soon 180 180.Consecutive_Numbers           Sql       Notes 181 181.Employees_Earning_More_Than_Thei...           Sql Coming soon 182 182.Duplicate_Emails           Sql Coming soon 183 183.Customers_Who_Never_Order           Sql       Notes 184 184.Department_Highest_Salary           Sql       Notes 186 186.Reverse_Words_in_a_String_II $        Not Buy     Not Buy 187 187.Repeated_DNA_Sequences Python Java C++ Coming soon 188 188.Best_Time_to_Buy_and_Sell_Stock_IV           C++       Notes 189 189.Rotate_Array           C++       Notes 190 190.Reverse_Bits Python Java C++       Notes 191 191.Number_of_1_Bits      Java C++       Notes 192 192.Word_Frequency         Shell       Notes 193 193.Valid_Phone_Numbers         Shell       Notes 194 194.Transpose_File         Shell       Notes 195 195.Tenth_Line         Shell       Notes 196 196.Delete_Duplicate_Emails           Sql Coming soon 197 197.Rising_Temperature           Sql       Notes 198 198.House_Robber           C++       Notes 199 199.Binary_Tree_Right_Side_View    Python C++       Notes 200 200.Number_of_Islands           C++       Notes 201 201.Bitwise_AND_of_Numbers_Range    Python C++       Notes 202 202.Happy_Number    Python C++       Notes 203 203.Remove_Linked_List_Elements Python Java C++       Notes 204 204.Count_Primes           C++ Coming soon 205 205.Isomorphic_Strings    Python C++       Notes 206 206.Reverse_Linked_List           C++ Coming soon 207 207.Course_Schedule    Python C++       Notes 208 208.Implement_Trie_(Prefix_Tree)           C++       Notes 209 209.Minimum_Size_Subarray_Sum           C++ Coming soon 210 210.Course_Schedule_II    Python C++       Notes 211 211.Add_and_Search_Word_-_Data_struc...               Coming soon 212 212.Word_Search_II               Coming soon 213 213.House_Robber_II               Coming soon 214 214.Shortest_Palindrome               Coming soon 215 215.Kth_Largest_Element_in_an_Array Python Java C++       Notes 216 216.Combination_Sum_III           C++       Notes 217 217.Contains_Duplicate    Python C++       Notes 218 218.The_Skyline_Problem               Coming soon 219 219.Contains_Duplicate_II           C++       Notes 220 220.Contains_Duplicate_III      Java C++       Notes 221 221.Maximal_Square    Python C++       Notes 222 222.Count_Complete_Tree_Nodes    Python C++       Notes 223 223.Rectangle_Area           C++       Notes 224 224.Basic_Calculator      Java C++       Notes 225 225.Implement_Stack_using_Queues      Java C++       Notes 226 226.Invert_Binary_Tree    Python C++       Notes 227 227.Basic_Calculator_II               Coming soon 228 228.Summary_Ranges    Python C++       Notes 229 229.Majority_Element_II               Coming soon 230 230.Kth_Smallest_Element_in_a_BST           C++       Notes 231 231.Power_of_Two    Python C++       Notes 232 232.Implement_Queue_using_Stacks    Python C++       Notes 233 233.Number_of_Digit_One               Coming soon 234 234.Palindrome_Linked_List Python Java C++       Notes 235 235.Lowest_Common_Ancestor_of_a_Bina...    Python C++       Notes 236 236.Lowest_Common_Ancestor_of_a_Binary_Tree               Coming soon 237 237.Delete_Node_in_a_Linked_List    Python C++       Notes 238 238.Product_of_Array_Except_Self Python Java C++       Notes 239 239.Sliding_Window_Maximum    Python C++       Notes 240 240.Search_a_2D_Matrix_II               Coming soon 241 241.Different_Ways_to_Add_Parentheses    Python C++       Notes 242 242.Valid_Anagram    Python C++       Notes 243 243.Shortest_Word_Distance $        Not Buy     Not Buy 244 244.Shortest_Word_Distance_II $        Not Buy     Not Buy 245 245.Shortest_Word_Distance_III $        Not Buy     Not Buy 246 246.Strobogrammatic_Number $        Not Buy     Not Buy 247 247.Strobogrammatic_Number_II $        Not Buy     Not Buy 248 248.Strobogrammatic_Number_III $        Not Buy     Not Buy 249 249.Group_Shifted_Strings $        Not Buy     Not Buy 250 250.Count_Univalue_Subtrees $        Not Buy     Not Buy 251 251.Flatten_2D_Vector $        Not Buy     Not Buy 252 252.Meeting_Rooms $        Not Buy     Not Buy 253 253.Meeting_Rooms_II $        Not Buy     Not Buy 254 254.Factor_Combinations $        Not Buy     Not Buy 255 255.Verify_Preorder_Sequence_in_Bina... $        Not Buy     Not Buy 256 256.Paint_House $        Not Buy     Not Buy 257 257.Binary_Tree_Paths    Python C++       Notes 258 258.Add_Digits    Python C++       Notes 259 259.3Sum_Smaller $        Not Buy     Not Buy 260 260.Single_Number_III               Coming soon 261 261.Graph_Valid_Tree $        Not Buy     Not Buy 263 263.Ugly_Number    Python C++       Notes 264 264.Ugly_Number_II               Coming soon 265 265.Paint_House_II $        Not Buy     Not Buy 266 266.Palindrome_Permutation $        Not Buy     Not Buy 267 267.Palindrome_Permutation_II $        Not Buy     Not Buy 268 268.Missing_Number Python Java C++       Notes 269 269.Alien_Dictionary $        Not Buy     Not Buy 270 270.Closest_Binary_Search_Tree_Value $        Not Buy     Not Buy 271 271.Encode_and_Decode_Strings $        Not Buy     Not Buy 272 272.Closest_Binary_Search_Tree_Value_II $        Not Buy     Not Buy 273 273.Integer_to_English_Words               Coming soon 274 274.H-Index               Coming soon 275 275.H-Index_II               Coming soon 276 276.Paint_Fence $        Not Buy     Not Buy 277 277.Find_the_Celebrity $        Not Buy     Not Buy 278 278.First_Bad_Version    Python C++       Notes 279 279.Perfect_Squares    Python C++       Notes 280 280.Wiggle_Sort $        Not Buy     Not Buy 281 281.Zigzag_Iterator $        Not Buy     Not Buy 282 282.Expression_Add_Operators               Coming soon 283 283.Move_Zeroes           C++       Notes 284 284.Peeking_Iterator               Coming soon 285 285.Inorder_Successor_in_BST $        Not Buy     Not Buy 286 286.Walls_and_Gates $        Not Buy     Not Buy 287 287.Find_the_Duplicate_Number               Coming soon 288 288.Unique_Word_Abbreviation $        Not Buy     Not Buy 289 289.Game_of_Life    Python C++       Notes 290 290.Word_Pattern    Python C++       Notes 291 291.Word_Pattern_II $        Not Buy     Not Buy 292 292.Nim_Game           C++       Notes 293 293.Flip_Game $        Not Buy     Not Buy 294 294.Flip_Game_II $        Not Buy     Not Buy 295 295.Find_Median_from_Data_Stream               Coming soon 296 296.Best_Meeting_Point $        Not Buy     Not Buy 297 297.Serialize_and_Deserialize_Binary_Tree               Coming soon 298 298.Binary_Tree_Longest_Consecutive_Sequence $        Not Buy     Not Buy 299 299.Bulls_and_Cows           C++ Coming soon 300 300.Longest_Increasing_Subsequence               Coming soon 301 301.Remove_Invalid_Parentheses               Coming soon 302 302.Smallest_Rectangle_Enclosing_Bla... $        Not Buy     Not Buy 303 303.Range_Sum_Query_-_Immutable               Coming soon 304 304.Range_Sum_Query_2D_-_Immutable               Coming soon 305 305.Number_of_Islands_II $        Not Buy     Not Buy 306 306.Additive_Number               Coming soon 307 307.Range_Sum_Query_-_Mutable               Coming soon 308 308.Range_Sum_Query_2D_-_Mutable $        Not Buy     Not Buy 309 309.Best_Time_to_Buy_and_Sell_Stock_...               Coming soon 310 310.Minimum_Height_Trees               Coming soon 311 311.Sparse_Matrix_Multiplication $        Not Buy     Not Buy 312 312.Burst_Balloons               Coming soon 313 313.Super_Ugly_Number               Coming soon 314 314.Binary_Tree_Vertical_Order_Traversal $        Not Buy     Not Buy 315 315.Count_of_Smaller_Numbers_After_Self               Coming soon 316 316.Remove_Duplicate_Letters               Coming soon 317 317.Shortest_Distance_from_All_Buildings $        Not Buy     Not Buy 318 318.Maximum_Product_of_Word_Lengths               Coming soon 319 319.Bulb_Switcher               Coming soon 320 320.Generalized_Abbreviation $        Not Buy     Not Buy 321 321.Create_Maximum_Number               Coming soon 322 322.Coin_Change               Coming soon 323 323.Number_of_Connected_Components_i... $        Not Buy     Not Buy 324 324.Wiggle_Sort_II               Coming soon 325 325.Maximum_Size_Subarray_Sum_Equals_k $        Not Buy     Not Buy 326 326.Power_of_Three Python Java C++       Notes 327 327.Count_of_Range_Sum               Coming soon 328 328.Odd_Even_Linked_List    Python C++       Notes 329 329.Longest_Increasing_Path_in_a_Matrix               Coming soon 330 330.Patching_Array               Coming soon 331 331.Verify_Preorder_Serialization_of...               Coming soon 332 332.Reconstruct_Itinerary               Coming soon 333 333.Largest_BST_Subtree $        Not Buy     Not Buy 334 334.Increasing_Triplet_Subsequence               Coming soon