C# week7_3

10/03/2010

Exception

try

{

---------

---------

}

catch(DividebyZero a)

{

---------

}

catch(Exception e)

{

---------

}

It will work.

 

try

{

---------

---------

}

catch(Exception e)

{

---------

}

catch(DividebyZero a)

{

---------

}

It won't work, because catch(DividebyZero a) class has never been executed, which is called 'unreachable code'. = error


 
Algorithms: a well-defined procedure to solve a problem


 
Sort Algorithm

• Bubble sort (one by one, taking long time)
  
• Exchange sort (similar to bubble sort, but slightly more efficient)
  
• Selection sort (search and sort, one of the least efficient)
  
• 
  
  
  Insertion sort
  • 
    
    
    two sub arrays
    • first sub array: sorted
      
    • second sub array: unsorted
      
  • first and efficient using with small arrays.
    
• 
  
  
  Quick sort
  • divide and conquer algorism
    
  • very efficient
    
• 
  
  
  Merge sort
  • two sorted arrays (MUST be SORTED FIRST)
    
  • more efficient but at the same time it is more complex
    
• 
  
  
  Bucket sort
  • counts array
    

 
Search Algorism

• 
  
  
  Liner search
  
  • best case: first element
    
  • worst case: last element
    
  • not efficient
    
• 
  
  
  Binary search
  • required a sorted array
    
  • array 0 to 9 (0+9)/2 = 4.5 find 4
    
  • (5+9)/2 = 7 find 7
    
  • (5+6)/2 = 5.5 find 5
    
  • (6+6)/2 = 6 find 6
    
  • more efficient