@@ -54,11 +54,11 @@
 | [Graph](https://.com/fluency03/leetcode-java/blob/master/src/graph) |
 
 
-# Total: 522
+# Total: 523
 
 | Easy | Medium | Hard | - |
 |:-------:|:-------:|:----:|:---:|
-| 139 | 284 | 87 | 11 |
+| 140 | 284 | 87 | 11 |
 
 
 | Question | Solution | Difficulty |
@@ -449,6 +449,7 @@
 | [554. Brick Wall](https://leetcode.com/problems/brick-wall/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/BrickWall554.java) | Medium |
 | [556. Next Greater Element III](https://leetcode.com/problems/next-greater-element-iii/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/NextGreaterElementIII556.java) | Medium |
 | [557. Reverse Words in a String III](https://leetcode.com/problems/reverse-words-in-a-string-iii/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/ReverseWordsInAStringIII557.java) | Easy |
+| [558. Quad Tree Intersection](https://leetcode.com/problems/quad-tree-intersection/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/QuadTreeIntersection558.java) | Easy |
 | [560. Subarray Sum Equals K](https://leetcode.com/problems/subarray-sum-equals-k/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/SubarraySumEqualsK560.java) | Medium |
 | [567. Permutation in String](https://leetcode.com/problems/permutation-in-string/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/PermutationInString567.java) | Easy |
 | [568. Maximum Vacation Days](https://leetcode.com/problems/maximum-vacation-days/) | [Solution](https://.com/fluency03/leetcode-java/blob/master/src/MaximumVacationDays568.java) | Hard |

@@ -0,0 +1,84 @@
+
+
+
+
+/*
+// Definition for a QuadTree node.
+class Node {
+public boolean val;
+public boolean isLeaf;
+public Node topLeft;
+public Node topRight;
+public Node bottomLeft;
+public Node bottomRight;
+
+public Node() {}
+
+public Node(boolean _val,boolean _isLeaf,Node _topLeft,Node _topRight,Node _bottomLeft,Node _bottomRight) {
+val = _val;
+isLeaf = _isLeaf;
+topLeft = _topLeft;
+topRight = _topRight;
+bottomLeft = _bottomLeft;
+bottomRight = _bottomRight;
+}
+};
+*/
+
+public class QuadTreeIntersection558 {
+public Node intersect(Node quadTree1, Node quadTree2) {
+if (quadTree1 == null || quadTree2 == null) {
+return null;
+}
+
+Node res = new Node();
+if (quadTree1.isLeaf && quadTree2.isLeaf) {
+res.isLeaf = true;
+res.val = quadTree1.val || quadTree2.val;
+return res;
+}
+
+res.topLeft = intersect(getTopLeft(quadTree1), getTopLeft(quadTree2));
+res.topRight = intersect(getTopRight(quadTree1), getTopRight(quadTree2));
+res.bottomLeft = intersect(getBottomLeft(quadTree1), getBottomLeft(quadTree2));
+res.bottomRight = intersect(getBottomRight(quadTree1), getBottomRight(quadTree2));
+
+if (allLeaves(res) && allSame(res)) {
+res.isLeaf = true;
+res.val = res.topLeft.val;
+return res;
+}
+return res;
+}
+
+private Node getTopLeft(Node n) {
+return n.isLeaf ? n : n.topLeft;
+}
+
+private Node getTopRight(Node n) {
+return n.isLeaf ? n : n.topRight;
+}
+
+private Node getBottomLeft(Node n) {
+return n.isLeaf ? n : n.bottomLeft;
+}
+
+private Node getBottomRight(Node n) {
+return n.isLeaf ? n : n.bottomRight;
+}
+
+private boolean allLeaves(Node n) {
+return n.topLeft.isLeaf &&
+n.topRight.isLeaf &&
+n.bottomLeft.isLeaf &&
+n.bottomRight.isLeaf;
+}
+
+private boolean allSame(Node n) {
+return (n.topLeft.val == n.topRight.val) &&
+(n.bottomLeft.val && n.bottomRight.val) &&
+(n.topLeft.val && n.bottomLeft.val);
+}
+
+}
+