@@ -55,11 +55,11 @@
 | [Graph](https://.com/fluency03/leetcode-java/blob/master/src/graph) |
 
 
-# Total: 535
+# Total: 536
 
 | Easy | Medium | Hard | - |
 |:-------:|:-------:|:----:|:---:|
-| 142 | 291 | 90 | 12 |
+| 142 | 292 | 90 | 12 |
 
 
 | Question | Solution | Difficulty |
@@ -492,6 +492,7 @@
 | [659. Split Array into Consecutive Subsequences](https://leetcode.com/problems/split-array-into-consecutive-subsequences/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/SplitArrayIntoConsecutiveSubsequences659.java) | Medium |
 | [661. Image Smoother](https://leetcode.com/problems/image-smoother/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/ImageSmoother661.java) | Easy |
 | [662. Maximum Width of Binary Tree](https://leetcode.com/problems/maximum-width-of-binary-tree/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/MaximumWidthOfBinaryTree662.java) | Medium |
+| [663. Equal Tree Partition](https://leetcode.com/problems/equal-tree-partition/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/EqualTreePartition663.java) | Medium |
 | [665. Non-decreasing Array](https://leetcode.com/problems/non-decreasing-array/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/NonDecreasingArray665.java) | Easy |
 | [669. Trim a Binary Search Tree](https://leetcode.com/problems/trim-a-binary-search-tree/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/TrimABinarySearchTree669.java) | Easy |
 | [671. Second Minimum Node In a Binary Tree](https://leetcode.com/problems/second-minimum-node-in-a-binary-tree/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/SecondMinimumNodeInABinaryTree671.java) | Easy |

@@ -0,0 +1,72 @@
+/**
+* Given a binary tree with n nodes, your task is to check if it's possible to
+* partition the tree to two trees which have the equal sum of values after
+* removing exactly one edge on the original tree.
+*
+* Example 1:
+* Input:
+* 5
+* / \
+* 10 10
+* / \
+* 2 3
+*
+* Output: True
+*
+* Explanation:
+* 5
+* /
+* 10
+* Sum: 15
+*
+* 10
+* / \
+* 2 3
+* Sum: 15
+*
+* Example 2:
+*
+* Input:
+* 1
+* / \
+* 2 10
+* / \
+* 2 20
+*
+* Output: False
+*
+* Explanation: You can't split the tree into two trees with equal sum after
+* removing exactly one edge on the tree.
+*
+* Note:
+* The range of tree node value is in the range of [-100000, 100000].
+* 1 <= n <= 10000
+*/
+
+/**
+* Definition for a binary tree node.
+* public class TreeNode {
+* int val;
+* TreeNode left;
+* TreeNode right;
+* TreeNode(int x) { val = x; }
+* }
+*/
+
+public class EqualTreePartition663 {
+public boolean checkEqualTree(TreeNode root) {
+Set<Integer> set = new HashSet<>();
+int total = sum(root, set, true);
+return total % 2 == 0 && set.contains(total / 2);
+}
+
+private int sum(TreeNode root, Set<Integer> set, boolean isRoot) {
+if (root == null) return 0;
+int left = sum(root.left, set, false);
+int right = sum(root.right, set, false);
+int s = left + root.val + right;
+if (!isRoot) set.add(s);
+return s;
+}
+
+}