|232|[Implement Queue using Stacks](https://leetcode.com/problems/implement-queue-using-stacks/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_232.java)| O(n)|O(n) | Medium| Stack, Design

|230|[Kth Smallest Element in a BST](https://leetcode.com/problems/kth-smallest-element-in-a-bst/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_230.java)| O(n)|O(k) | Medium| Tree

|229|[Majority Element II](https://leetcode.com/problems/majority-element-ii/)|[Solution](../master/src/main/java/com/fishercoder/solutions/MajorityElementII.java)| O(n)|O(n) | Medium|

|227|[Basic Calculator II](https://leetcode.com/problems/basic-calculator-ii/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_227.java)| O(n)|O(n) | Medium| String

|226|[Invert Binary Tree](https://leetcode.com/problems/invert-binary-tree/)|[Solution](../master/src/main/java/com/fishercoder/solutions/InvertBinaryTree.java)| O(n)|O(h) | Easy| DFS, recursion

|225|[Implement Stack using Queues](https://leetcode.com/problems/implement-stack-using-queues/)|[Solution](../master/src/main/java/com/fishercoder/solutions/ImplementStackUsingQueues.java)| O(n)|O(n) | Easy| Stack, Queue

public static List<String> summaryRanges(int[] nums) {

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