Computer Notes Useful for Students
Lecture Notes
CMSC 251
CMSC 251: Algorithms1 Spring 1998 Dave Mount Lecture 1: Course Introduction
(Tuesday, Jan 27, 1998)
Read: Course syllabus and Chapter 1 in CLR (Cormen, Leiserson, and Rivest). What is algorithm design? Our text defines an algorithm to be any well-defined computational procedure that takes some values as input and produces some values as output. Like a cooking recipe, an algorithm provides a step-by-step method for solving a computational problem. A good understanding of algorithms is essential for a good understanding of the most basic element of computer science: programming. Unlike a program, an algorithm is a mathematical entity, which is independent of a specific programming language, machine, or compiler. Thus, in some sense, algorithm design is all about the mathematical theory behind the design of good programs. Why study algorithm design? There are many facets to good program design. Good algorithm design is one of them (and an important one). To be really complete algorithm designer, it is important to be aware of programming and machine issues as well. In any important programming project there are two major types of issues, macro issues and micro issues. Macro issues involve elements such as how does one coordinate the efforts of many programmers working on a single piece of software, and how does one establish that a complex programming system satisfies its various requirements. These macro issues are the primary subject of courses on software engineering. A great deal of the programming effort on most complex software systems consists of elements whose programming is fairly mundane (input and output, data conversion, error checking, report generation). However, there is often a small critical portion of the software, which may involve only tens to hundreds of lines of code, but where the great majority of computational time is spent. (Or as the old adage goes: 80% of the execution time takes place in 20% of the code.) The
CMSC 251
CMSC 251: Algorithms1 Spring 1998 Dave Mount Lecture 1: Course Introduction
(Tuesday, Jan 27, 1998)
Read: Course syllabus and Chapter 1 in CLR (Cormen, Leiserson, and Rivest). What is algorithm design? Our text defines an algorithm to be any well-defined computational procedure that takes some values as input and produces some values as output. Like a cooking recipe, an algorithm provides a step-by-step method for solving a computational problem. A good understanding of algorithms is essential for a good understanding of the most basic element of computer science: programming. Unlike a program, an algorithm is a mathematical entity, which is independent of a specific programming language, machine, or compiler. Thus, in some sense, algorithm design is all about the mathematical theory behind the design of good programs. Why study algorithm design? There are many facets to good program design. Good algorithm design is one of them (and an important one). To be really complete algorithm designer, it is important to be aware of programming and machine issues as well. In any important programming project there are two major types of issues, macro issues and micro issues. Macro issues involve elements such as how does one coordinate the efforts of many programmers working on a single piece of software, and how does one establish that a complex programming system satisfies its various requirements. These macro issues are the primary subject of courses on software engineering. A great deal of the programming effort on most complex software systems consists of elements whose programming is fairly mundane (input and output, data conversion, error checking, report generation). However, there is often a small critical portion of the software, which may involve only tens to hundreds of lines of code, but where the great majority of computational time is spent. (Or as the old adage goes: 80% of the execution time takes place in 20% of the code.) The