数据结构 授课课件 Data structure.ppt

Data structure
Basic Concept
Data
The set of symbols which can be recognized, stored and processed by puter.
Is the carrier of information.
Examples
Integer or real. (processed by digital processing programs)
Source program.( processed piler)
Images. (processed by image processing programs)
Basic Concept
Data element
The basic unit pose a data.
Can also be referred as element, record, node or vertex.
Data item
Data element posed by data items.
Is the smallest unit discussed in data structure.
Data item is also called domain or field.
Basic Concept
Data structure
The set of data elements which have some relationship between each other.
Logical structure
The logical relationship between each other.
Storage structure
Storage map of logical structure in storage.
Basic Concept
The logical structure can be formally represented as : L = ( N, R )N: the set of the node. R: the set of relation on N.
Examples
L = ( N, R ) N = { a0, a1, a2 } R = { r } r = { ( a0, a1 ), ( a0, a2 ) }
Basic Concept
Let L=( N, R ) is a logical structure, R={ r },If a, b∈N, and relation ( a, b )∈R,
then : a is predecessor node of b b is essor node of b a and b are adjacent nodes If a node don’t have predecessor, it is called start node. If a node don’t have essor, it is called final node. If a node have both predecessor and essor, it is called internal node.
Basic Concept
Logical structure of data
Liner structure
Tree structure
Graph structure
Set structure
Basic Structure
Linear StructureThere is only one start node and final node, every internal node have one and only one predecessor and essor.
None linear structureNodes in the structure can have more than one predecessor and essor.
Basic concept
Every line represents a node (element), every line posed of 9 domains (data items).
The first line is start node, the last line is final node. The lines between the first line and last line are internal nodes.
The logical structure of a table is linear structure.
Bas