public static int topK(int[] arr, int k) { if (arr == null || k > arr.length || arr.length == 0 || k <= 0) { return -1;...

private TreeNode buildTree(Integer[] array, int index) { TreeNode treeNode; if (index < array.length) { Integer value =...

public class LRUCache<K,V>{ private final int cap; private final Map<K,V> map; private final LinkedList<K> list; public...