update

Author: shishishu

README.md

@@ -7,7 +7,7 @@ Idx | Date | Question | Python| Java | Domain | Tag | Difficulty | Remark
 001|20190626|[54. Spiral Matrix](https://leetcode.com/problems/spiral-matrix/)|[054p](https://github.com/shishishu/leetcode-python-java/blob/master/ipynb_files/054_Spiral_Matrix.ipynb)|[054j](https://github.com/shishishu/leetcode-python-java/blob/master/java_codes/054/Solution.java)|Matrix| |Medium
 002|20190626|[59. Spiral Matrix II](https://leetcode.com/problems/spiral-matrix-ii/)|[059p](https://github.com/shishishu/leetcode-python-java/blob/master/ipynb_files/059_Spiral_Matrix_II.ipynb)|[059j](https://github.com/shishishu/leetcode-python-java/blob/master/java_codes/059/Solution.java)|Matrix| |Medium
 003|20190627|[53. Maximum Subarray](https://leetcode.com/problems/maximum-subarray/)|[053p](https://github.com/shishishu/leetcode-python-java/blob/master/ipynb_files/053_Maximum_Subarray.ipynb)|[053j](https://github.com/shishishu/leetcode-python-java/blob/master/java_codes/053/Solution.java)|Array|DP|Easy|
-004|20190627|[220. Contains Duplicate III](https://leetcode.com/problems/contains-duplicate-iii/)|[220p](https://github.com/shishishu/leetcode-python-java/blob/master/ipynb_files/220_Contains_Duplicate_III.ipynb)|[220j](https://github.com/shishishu/leetcode-python-java/blob/master/java_codes/220/Solution.java)|Array| |Medium|pending: [use buckets](https://leetcode.com/problems/contains-duplicate-iii/discuss/61645/AC-O(N)-solution-in-Java-using-buckets-with-explanation)
+004|20190627|[220. Contains Duplicate III](https://leetcode.com/problems/contains-duplicate-iii/)|[220p](https://github.com/shishishu/leetcode-python-java/blob/master/ipynb_files/220_Contains_Duplicate_III.ipynb)|[220j](https://github.com/shishishu/leetcode-python-java/blob/master/java_codes/220/Solution.java)|Array| |Medium|
 005|20191013|[101. Symmetric Tree](https://leetcode.com/problems/symmetric-tree/)|[101p](https://github.com/shishishu/leetcode-python-java/blob/master/ipynb_files/101_Symmetric_Tree.ipynb)|[101j](https://github.com/shishishu/leetcode-python-java/blob/master/java_codes/101/Solution.java)|Tree|Recursive|Easy
 006|20191013|[102. Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/)|[102p](https://github.com/shishishu/leetcode-python-java/blob/master/ipynb_files/102_Binary_Tree_Level_Order_Traversal.ipynb)|[102j](https://github.com/shishishu/leetcode-python-java/blob/master/java_codes/102/Solution.java)|Tree|Iterative|Medium
 007|20191020|[104. Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/)|[104p](https://github.com/shishishu/leetcode-python-java/blob/master/ipynb_files/104_Maximum_Depth_of_Binary_Tree.ipynb)|[104j](https://github.com/shishishu/leetcode-python-java/blob/master/java_codes/104/Solution.java)|Tree|BFS/DFS|Easy