CSE 2011 Lecture 1

Course Information

Website: http://www.cse.yorku.ca/course/2011/

Workload: 3 reports(6%,7%,7%), 2 class tests(20%,20%) and a final exam(40%).

Course directly for prism: prism:/cse/course/2011

• Found here:
  
  • Java files for assignments
    
  • Answers for assignments
    
• To find your grade:
  
  • Console: courseInfo 2011 [2007-08 W]
    

 

• Data structures
  
  • A systematic way to organize and access data
    
    • That is easy to retrieve
      
  • Algorithm
    
    • Step by step procedure for performing some task in a finite amount of time
      
    • "Sometimes you want to use the slower algorithms because they are faster"
      
  • Programs = Data Structures + Algorithms
    
    • The course forms a framework for developing useful programs
      
• Principles of public design
  
  • Principle of use
    
    • Programs will be used by people
      
    • They are public
      
    • Must be designed for people
      
  • Principle of misuse
    
    • Programs will be misused by people
      
  • Principle of evolution
    
    • Programs will be changed by people
      
    • If you want to modify it you'll have to know how it works
      
  • Principle of migration
    
    • Programs will be moved to new environments by people
      
• Software quality
  
  • Readable and understandable
    
    • All design artifacts – program text included – are primarily to be read and used by people
      
    • Execution is incidental
      
  • Correct and complete
    
    • It works – it is useable
      
    • Works correctly for all possible inputs that one might encounter within a domain of interest
      
  • First write correct programs then worry about efficiency
    
    • A fast program that is wrong is worse than useless
      
    • Speed up where necessary after instrumentation
      
    • Always design to be as efficient as you wanted to be and no more
      
  • Efficient as it needs to be
    
    • Use an appropriate amount of resources for the task
      
      • Space for storing data and temporary results
        
      • Execution time
        
      • Space – time tradeoff
        
      • Communications bandwidth
        
  • Modifiable
    
    • All programs evolve over time
      
    • Make plausible modifications easy
      
      • One sign of a good design is it is easy to modify and adapt to changing circumstances
        
  • On time and on budget
    
    • Time is money
      
      • Pay back on investment
        
    • Imbedded systems
      
      • Programs are only a part of the system
        
• Basic data structures
  
  • Array
    
    • Single type of data
      
    • Fixed size
      
    • homogeneous
      
  • Tuple
    
    • Collection of different types of data
      
    • Heterogeneous
      
• We want to store things in a container of the basic data structures
  
• We want to organize data structures
  
• A container should be able to:
  
  • Add
    
  • Remove
    
  • Retrieve
    
  • Find size
    
    • How big the container is
      
    • How many things are in the container
      
    • If it contains something
      
  • organize
    
• A fundamental organization of a collection
  
  • Iteration
    
  • Move elements
    
• Fundamental property of a sequence
  
  • The beginning and the end of the sequence
    
  • There is a front a sequence and a rear to a sequence
    
• A list is the organization of a container
  
•