|257|[Binary Tree Paths](https://leetcode.com/problems/binary-tree-paths/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_257.java) | O(n*h) | O(h) | DFS/Recursion

|256|[Paint House](https://leetcode.com/problems/paint-house/)|[Solution](../master/src/main/java/com/fishercoder/solutions/PaintHouse.java) | O(n) | O(1) | Medium| DP

|255|[Verify Preorder Sequence in Binary Search Tree](https://leetcode.com/problems/verify-preorder-sequence-in-binary-search-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_255.java) | O(n) | O(h) | Medium| Tree

|253|[Meeting Rooms II](https://leetcode.com/problems/meeting-rooms-ii/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_253.java) | O(nlogn) | O(h) | Medium| Heap

|252|[Meeting Rooms](https://leetcode.com/problems/meeting-rooms/)|[Solution](../master/src/main/java/com/fishercoder/solutions/MeetingRooms.java) | O(nlogn) | O(1) | Easy

|251|[Flatten 2D Vector](https://leetcode.com/problems/flatten-2d-vector/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_251.java)| O(1)|O(m*n) | Medium|

public List<List<Integer>> getFactors(int n) {

List<List<Integer>> result = new ArrayList<List<Integer>>();