Min Chen School of Computer Science and Engineering Seoul National University Data Structure: Chapter 1

 What is Data Structure  The Importance of Data Structure  Type of Data Structure

 Data structures are ways in which data is arranged in your computer’s memory (or stored on disk).  Algorithms are the procedures a software program uses to manipulate the data in these structures.

 Almost every computer program, even a simple one, uses data structures and algorithms.  Example:  Program: To print a address list ▪ Data Structure: Array ▪ Algorithm: Loop Program = Data Structure + Algorithm

 Arrays  Ordered Array  Stacks  Queues  Priority Queues  Linked Lists  Tree  Binary Tree  Hash Table  Heap

 A container to be filled with elements (0,0) (4,2)  Each element can be accessed via unique remark Fig.1 A 2-Dimensional Array

 You can only eat the top apple first  FILO (First In Last Out) Fig.2 An Apple Stack

 The one came first can get the ticket first  FIFO(First In First Out) Fig.3 A Queue for Tickets

 A linear sequence, but the Storage of elements is always not linear Data Link  Each record contains a reference (i.e., a link) to the next record in the sequence Fig.4 A Gold Chain

 Start from the root, end at the leaves  No loop allowed Is Not a Tree in Data Structure Is a Tree in Data Structure Fig.5 A Family Tree of AbramFig.6 An Unusual Family Tree