Currently, we have also written public notes about VisuAlgo in various languages: If you are using VisuAlgo and spot a bug in any of our visualization page/online quiz tool or if you want to request for new features, please contact Dr Steven Halim. This online quiz system, when it is adopted by more CS instructors worldwide, should technically eliminate manual basic data structure and algorithm questions from typical Computer Science examinations in many Universities. It We will soon add the remaining 8 visualization modules so that every visualization module in VisuAlgo have online quiz component. If you take screen shots (videos) from this website, you can use the screen shots (videos) elsewhere as long as you cite the URL of this website ( and/or list of publications below as reference. Currently, the general public can only use the 'training mode' to access these online quiz system. You can click this link to read our 2012 paper about this system (it was not yet called VisuAlgo back in 2012). Truong Ngoc Khanh, John Kevin Tjahjadi, Gabriella Michelle, Muhammad Rais Fathin Mudzakir. This is an online tool for phylogenetic tree view (newick format) that allows multiple sequence alignments to be shown together with the trees (fasta format). You can create RMinQ/RMaxQ/RSumQ Segment Tree from either a user-defined array of integers (maximum of 16 two-digits integer), or let the system provide a small random integer array or a small random but sorted integer array. Drop an email to at gmail dot com if you want to activate this CS lecturer-only feature and you are really a CS lecturer (show your University staff profile). VisuAlgo is an ongoing project and more complex visualisations are still being developed. This project is made possible by the generous Teaching Enhancement Grant from NUS Centre for Development of Teaching and Learning (CDTL). Control the animation with the player controls! Jonathan Irvin Gunawan, Nathan Azaria, Ian Leow Tze Wei, Nguyen Viet Dung, Nguyen Khac Tung, Steven Kester Yuwono, Cao Shengze, Mohan Jishnu, Final Year Project/UROP students 3 (Jun 2014-Apr 2015) Tip: Use NCBI numeric taxids as leaf names (or in the format TaxID.sequenceName) to get on-the-fly translation of species names and lineages. It uses the tree drawing engine implemented in the ETE toolkit, and offers transparent integration with the NCBI taxonomy database. We employ lazy update strategy for fast performance. allows multiple sequence alignments to be shown together with the trees (fasta format). Enter an integer key and click the Search button to search the key in the tree. Phylogenetic tree (newick) viewer. e-Lecture: The content of this slide is hidden and only available for legitimate CS lecturer worldwide. Click the Insert button to insert the key into the tree. Dr Felix Halim, Software Engineer, Google (Mountain View), Undergraduate Student Researchers 1 (Jul 2011-Apr 2012) Keyboard shortcuts are: Return to 'Exploration Mode' to start exploring! Using the offline copy of (client-side) VisuAlgo for your personal usage is fine. You can do Range Update by specifying a left (L) index, a right (R) index, and a new VALUE for this range [L,R]. VisuAlgo is not a finished project. Remarks: By default, we show e-Lecture Mode for first time (or non logged-in) visitor. The questions are randomly generated via some rules and students' answers are instantly and automatically graded upon submission to our grading server. There are three basic operations that are available in Segment Tree data structure visualization (for all 3 modes: RMinQ/RMaxQ/RSumQ):1. The most exciting development is the automated question generator and verifier (the online quiz system) that allows students to test their knowledge of basic data structures and algorithms. the NCBI taxonomy database. Leaf names in the newick tree should match Pro-tip: Since you are not logged-in, you may be a first time visitor who are not aware of the following keyboard shortcuts to navigate this e-Lecture mode: [PageDown] to advance to the next slide, [PageUp] to go back to the previous slide, [Esc] to toggle between this e-Lecture mode and exploration mode. Another pro-tip: We designed this visualization and this e-Lecture mode to look good on 1366x768 resolution or larger (typical modern laptop resolution in 2017). Erin Teo Yi Ling, Wang Zi, Final Year Project/UROP students 4 (Jun 2016-Dec 2017) The minimum screen resolution for a respectable user experience is 1024x768 and only the landing page is relatively mobile-friendly. However, you are NOT allowed to download VisuAlgo (client-side) files and host it on your own website as it is plagiarism. Today, some of these advanced algorithms visualization/animation can only be found in VisuAlgo. Though specifically designed for National University of Singapore (NUS) students taking various data structure and algorithm classes (e.g. Again, you are free to customize this custom library implementation to suit your needs. By setting a small (but non-zero) weightage on passing the online quiz, a CS instructor can (significantly) increase his/her students mastery on these basic questions as the students have virtually infinite number of training questions that can be verified instantly before they take the online quiz. This is a big task and requires crowdsourcing. Dr Steven Halim is still actively improving VisuAlgo. Please login if you are a repeated visitor or register for an (optional) free account first. Click the Remove button to remove the key from the tree. To toggle between the RMinQ/RMaxQ/RSumQ Segment Tree, select the respective header. Once the system is ready, we will invite VisuAlgo visitors to contribute, especially if you are not a native English speaker. uses the tree drawing engine implemented in the ETE toolkit, and offers transparent integration with List of translators who have contributed ≥100 translations can be found at statistics page. This work is done mostly by my past students. View the visualisation of Segment Tree here!The top side shows the Segment Tree structure where each vertex shows the Min/Max/Sum value of the corresponding range (red colored with this format [L,R]).The bottom row shows the original array A content (yellow colored) from which the Segment Tree structure is built.Vertices that are lazily updated will have this purple ring highlight.Each leaf vertex in the Segment Tree corresponds to an individual index in the corresponding array A. His contact is the concatenation of his name and add gmail dot com. VisuAlgo was conceptualised in 2011 by Dr Steven Halim as a tool to help his students better understand data structures and algorithms, by allowing them to learn the basics on their own and at their own pace. Currently the 'test mode' is a more controlled environment for using these randomly generated questions and automatic verification for a real examination in NUS.