brightlightkim

A tree is actually a type of graph, but not all graphs are trees. Simply put, a tree is a connected graph without cycles. A graph is simply a collection of nodes with edges between (some of) them. Graphs can be either directed (like the following graph) or undirected. While directed edges are like a one way street, undirected edges are like a two way street The graph might consist of multiple is..

Min Heap: A complete binary tree (that is filled other than the rightmost elements on the last level) where each node is smaller than its children. The root, therefore, is the minimum element in the tree. We have two key operations on a min-heap: insert and extract_min Insert When we insert into a min-heap, we always start by inserting the element at the bottom. We insert it at the rightmost spo..

2.2 Implement an algorithm to find the kth to last element of a singly linked list. public Node returnKthToLast(Node node, int k){ Node n = node; int i = 0; while (n.next != null){ if (i == k-1){ break; } i++; n = n.next; } return n; } This was so simple, but I found out that this algorithm is not what the potential interviewer is looking for. It's more like.. int printKthToLast(Node head, int k..

A Linked list is a data structure that represents a sequence of nodes. In a singly linked list, each node points to the next node in the linked list. A doubly linked list gives each node pointers to both the next node and the previous one. Unlike an array, a linked list does not provide constant-time access to a particular "index' within the list. This means that if you'd like to find the K'th e..

Hash Tables A data structure that maps keys to values for highly efficient lookup. 1. Compute the key's hash code, usually an int or long. Note that two different keys could have the same hash code, as there may be an infinite number of keys and a finite number of ints 2. Then, map the hash code to an index in the array. This could be done with something like hash(key) % array_length. Two differ..