PPT-CSE 421 Greedy Algorithms / Caching Problem

Yin Tat Lee 1 2 Optimal CachingPaging Memory systems Many levels of storage with different access times Smaller storage has shorter access time To access an item it must be brought to the lowest level of the memory system. Chapter . 3. Sec 3.1 &3.2. With Question/Answer Animations. 1. Chapter Summary. Algorithms . Example Algorithms . Algorithmic Paradigms. Growth of Functions. Big-. O. and other Notation. Complexity of Algorithms. Optimization problems, Greedy Algorithms, Optimal Substructure and Greedy choice. Learning & Development Team. http://academy.telerik.com. . Telerik Software Academy. Table of Contents. Optimization Problems. 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 . 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. to . Greedy Routing Algorithms . in Ad-Hoc Networks. ○. Truong . Minh . Tien. Joint work with. Jinhee. . Chun, . Akiyoshi. . Shioura. , . and Takeshi . Tokuyama. Tohoku University. Japan. Our . Problem. 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!. Applications. Lecture 5. : Sparse optimization. Zhu Han. University of Houston. Thanks Dr. . Shaohua. Qin’s efforts on slides. 1. Outline (chapter 4). Sparse optimization models. Classic solvers and omitted solvers (BSUM and ADMM). 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. 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. Caching Problem. Yin Tat Lee. 1. 2. Last Lecture. Greedy . Analysis Strategies. Greedy algorithm stays ahead: Induction. Structural: Come up with a lower bound. Exchange argument: transform OPT to . greedy. CSE 421 Greedy Algorithms / Interval Scheduling Yin Tat Lee 1 Interval Scheduling Job starts at and finishes at . Two jobs compatible if they don’t overlap. Goal: find maximum subset of mutually compatible jobs. 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. 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..