PPT-Greedy Algorithms

CIS 606 Spring 2010 Greedy Algorithms Similar to dynamic programming Used for optimization problems Idea When we have a choice to make make the one that looks best right now Make a locally . Yoshua. . Bengio. , Pascal . Lamblin. , Dan . Popovici. , Hugo . Larochelle. NIPS 2007. Presented by . Ahmed . Hefny. Story so far …. Deep neural nets are more expressive: Can learn wider classes of functions with less . . Greedy . Algorithms. CSE 680. Prof. Roger Crawfis. Optimization . Problems. For most optimization problems you . want to find, not just . a. solution, but the . best. . solution.. A . greedy algorithm . A Mini-Survey. Chandra . Chekuri. Univ. of Illinois, Urbana-Champaign. Submodular Set Functions. A function . f. : 2. N. . . . R . is submodular if. . f(A. ) + . f(B. ) ≥ . f(A. . B. ) + . Optimization problems, Greedy Algorithms, Optimal Substructure and Greedy choice. Learning & Development Team. http://academy.telerik.com. . Telerik Software Academy. Table of Contents. Optimization Problems. Yuli. Ye . Joint work with Allan Borodin, University of Toronto. Why do we study greedy algorithms? . don’t. A quote from Jeff Erickson’s algorithms book. . Everyone should tattoo the following sentence on the back of their hands, right under all the rules about logarithms and big-Oh notation. The two key components. Optimal Sub-structure. You solve the problem by solving a sub-problem optimally. Greedy Property. Using the choice that seems best at the moment leads to the optimal result. This is tougher to show!. Greedy algorithms, coin changing problem. Haidong. . Xue. Summer 2012, at GSU. What is a greedy algorithm?. Greedy algorithm. : “an algorithm always makes the choice that looks best at the moment”. Announcements. I am not Prof. Rubinstein. He will be back next week. My name is Mary Wootters. New HW posted today!. Roadmap. Sorting. Graphs!. Longest, Shortest, Max and Min. …. Data structures. Asymptotic Analysis. Fall . 2011. Sukumar Ghosh. What is an algorithm. . A finite set (or sequence) of . precise instructions . for performing a computation. . . . Example: Maxima finding. . . procedure . max. (. Overarching principle – Take the choice that looks best at the current moment.. More efficient than dynamic programming . Always make the choice that looks “best” at the moment (just one . choice; . Dynamic and Online Algorithms: Anupam Gupta Carnegie Mellon University Based on joint works with: Albert Gu, Guru Guruganesh, Ravishankar Krishnaswamy, Amit Kumar, Debmalya Panigrahi, Cliff Stein, and David Wajc Fall 20151 Week . 7. CSCI-141. Scott C. Johnson. Say we go to the bank to cash our paycheck. We ask the teller for the fewest bills and coins as possible. Moments later the teller gives us our money and we leave. Minimum spanning tree (MST). Single source shortest path (SSSP), e.g., Dijkstra’s algorithm. We will explore the main properties, with focus on theoretical foundations. MST:. Graph G(V,E): undirected, connected, weighted (arbitrary real weights w() on edges). Instructor. : . S.N.TAZI. . ASSISTANT PROFESSOR ,DEPTT CSE. GEC AJMER. satya.tazi@ecajmer.ac.in. 3. -. 2. A simple example. Problem. : Pick k numbers out of n numbers such that the sum of these k numbers is the largest..