Table Of Content

Contents Page: v Preface Page: ix 1 What Are Algorithms and Why Should You Care? Page: 1 Correctness Page: 2 Resource usage Page: 4 Computer algorithms for non-computer people Page: 6 Computer algorithms for computer people Page: 6 Further reading Page: 8 2 How to Describe and Evaluate Computer Algorithms Page: 10 How to describe computer algorithms Page: 10 How to characterize running times Page: 17 Loop invariants Page: 21 Recursion Page: 22 Further reading Page: 24 3 Algorithms for Sorting and Searching Page: 25 Binary search Page: 28 Selection sort Page: 32 Insertion sort Page: 35 Merge sort Page: 40 Quicksort Page: 49 Recap Page: 57 Further reading Page: 59 4 A Lower Bound for Sorting and How to Beat It Page: 60 Rules for sorting Page: 60 The lower bound on comparison sorting Page: 61 Beating the lower bound with counting sort Page: 62 Radix sort Page: 68 Further reading Page: 70 5 Directed Acyclic Graphs Page: 71 Directed acyclic graphs Page: 74 Topological sorting Page: 75 How to represent a directed graph Page: 78 Running time of topological sorting Page: 80 Critical path in a PERT chart Page: 80 Shortest path in a directed acyclic graph Page: 85 Further reading Page: 89 6 Shortest Paths Page: 90 Dijkstra’s algorithm Page: 92 The Bellman-Ford algorithm Page: 101 The Floyd-Warshall algorithm Page: 106 Further reading Page: 114 7 Algorithms on Strings Page: 115 Longest common subsequence Page: 115 Transforming one string to another Page: 121 String matching Page: 129 Further reading Page: 136 8 Foundations of Cryptography Page: 138 Simple substitution ciphers Page: 139 Symmetric-key cryptography Page: 140 Public-key cryptography Page: 144 The RSA cryptosystem Page: 146 Hybrid cryptosystems Page: 155 Computing random numbers Page: 156 Further reading Page: 157 9 Data Compression Page: 158 Huffman codes Page: 160 Fax machines Page: 167 LZW compression Page: 168 Further reading Page: 178 10 Hard? Problems Page: 179 Brown trucks Page: 179 The classes P and NP and NP-completeness Page: 183 Decision problems and reductions Page: 185 A Mother Problem Page: 188 A sampler of NP-complete problems Page: 190 General strategies Page: 205 Perspective Page: 208 Undecidable problems Page: 210 Wrap-up Page: 211 Further reading Page: 212 Bibliography Page: 213 Index Page: 215

Description:

For anyone who has ever wondered how computers solve problems, an engagingly written guide for nonexperts to the basics of computer algorithms. Have you ever wondered how your GPS can find the fastest way to your destination, selecting one route from seemingly countless possibilities in mere seconds? How your credit card account number is protected when you make a purchase over the Internet? The answer is algorithms. And how do these mathematical formulations translate themselves into your GPS, your laptop, or your smart phone? This book offers an engagingly written guide to the basics of computer algorithms. In Algorithms Unlocked, Thomas Cormen—coauthor of the leading college textbook on the subject—provides a general explanation, with limited mathematics, of how algorithms enable computers to solve problems. Readers will learn what computer algorithms are, how to describe them, and how to evaluate them. They will discover simple ways to search for information in a computer; methods for rearranging information in a computer into a prescribed order (“sorting”); how to solve basic problems that can be modeled in a computer with a mathematical structure called a “graph” (useful for modeling road networks, dependencies among tasks, and financial relationships); how to solve problems that ask questions about strings of characters such as DNA structures; the basic principles behind cryptography; fundamentals of data compression; and even that there are some problems that no one has figured out how to solve on a computer in a reasonable amount of time.