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Show Source |    | About   «  Preface   ::   Contents   ::   1.1. Data Structures and Algorithms  »

17.1. Data Structures and Algorithm Analysis Introduction

17.1.1. Introduction

17.1.1.1. Course Introduction

Goals of this Course

  • Reinforce the concept that costs and benefits exist for every data structure.

  • Learn the commonly used data structures.
    • These form a programmer’s basic data structure “toolkit”.

  • Understand how to measure the cost of a data structure or program.
    • These techniques also allow you to judge the merits of new data structures that you or others might invent.

17.1.1.2. Costs and Benefits

  • Each data structure has costs and benefits.
    • Rarely is one data structure better than another in all situations.

  • Any data structure requires:
    • space for each data item it stores,

    • time to perform each basic operation,

    • programming effort.

  • Only after a careful analysis of problem characteristics can we know the best data structure for a task.

17.1.1.3. Data Structure

  • A data structure is the physical implementation of an ADT.
    • Each operation associated with the ADT is implemented by one or more subroutines in the implementation.

  • Data structure usually refers to an organization for data in main memory.

  • File structure: an organization for data on peripheral storage, such as a disk drive.

17.1.1.4. Logical vs. Physical Form

  • Data items have both a logical and a physical form.

  • Logical form: definition of the data item within an ADT.

    • Ex: Integers in mathematical sense: +, -

  • Physical form: implementation of the data item within a data structure.

    • Ex: 32/64 bit integers, overflow.

17.1.1.5. Logical vs. Physical Form (2)

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