An adjacency matrix is a 2d array representing a graph. The nodes are the headings for the rows and columns. The element in the cell indicates whether an edge is present between two nodes. Depth first search (DFS) is an algorithm used to traverse or search in a graph. The …
In mathematics expressions, there are infix, prefix and postfix notations. Infix notation is characterized by the placement of operators between operands. For example, the plus sign in 2 + 2. Prefix notation is a notation in which operators precede their operands, such as + 3 4. Postfix notation is a …
Huffman coding is an algorithm to generate the binary code based on the frequencies of corresponding characters in the input string. Huffman decoding is to recover the original text from the binary code generated from the huffman coding process. By applying huffman algorithms, we compress the input string by using …
Autocomplete is a feature that search box returns the suggestions based on what you have typed. Autocomplete with trie provides an implementation of auto-complete by using data structure trie. A trie is a tree-like data structure in which every node stores a character. After building the trie, strings or substrings …
Web scraping is a great way to retrieve data and save the information. with a simple Java web scraping setup, you can download content using Jsoup and selenium. Download the source code from the GitHub. Table of Content Web scraping and parsing in HTML – Jsoup Download images – Jsoup …
Dijkstra’s algorithm is an algorithm to find the shortest paths between vertices in a graph. It uses greedy technique by picking the un-visited vertex with the lowest distance. When all vertices have been evaluated, the result is the shortest path. This post provides code to find shortest path and second …
Get suggested friends is one of a coding question in social network applications. The data structures for social network is usually a graph. In the graph, you can use depth first search(DFS) or breadth first search(BFS) to find the connections between people. Alternatively, you can also use Union find to …
An Euler path is a trail in a graph that visits every edge exactly once. Here we use graph data structure to simulate the set of linked porker cards and find the Euler path between them. In a porker game, if two poker cards have matched suites and figures, they can be link together. Given …
The K closest problem is to find K closest points to the pointer(0,0) (it is called center or origin). The input k is to specify how many points you should return. The Euclidean distance formula is √[ (x2–x1)^2 + (y2–y1)^2]. For this question, we don’t need to calculate the actual …
Shortest path in matrix is to find the shortest distance from the the source to the destination. As you know, graph can be represented as adjacent matrix. Therefore, we can use the Breadth First Search algorithm in graph to solve this problem. BFS starts from the source node. It explores …
