CompSci 6 Test 1 Spring 2010

1. A. Output
x/z = 1
x/y = 2.5
multiply 15
6.0
urh
now?
9 12 6 7 done



B. 1. int
   2. in and status
   3. Scanner and String
   4. 3
   5. It reads data from a file in which each line has a name, an age, and
       a condition. It returns the number of people in the file that have a 
       specified condition, where the condition is a parameter. 


C. Two rectangles are drawn. A red rectangle is drawn with its top left
corner at (50,100), width 50 and height 100. A green rectangle is drawn
with its top left corner at (100, 200), width 50 and height 100.



2. 
public double averageInRange(int [] numbers, int low, int high)           
{                 
   double average = 0;                        
   int count = 0;               
   for (int value: numbers)                   
   {              
      if (value >= low && value <= high)                    
      {                         
         count++;               
         average += value;                    
      }                         
   }              
   return average/count;                      
}              



ALT SOLN:
public double averageInRange(int [] numbers, int low, int high)
{
   double average = 0; 
   int count = 0; 
   for (int k=0; k<numbers.length; k++)
   {    
      if (numbers[k] >= low && numbers[k] <= high)
      {  
         count++;  
         average += numbers[k]; 
      }  
   }   
   return average/count; 
}              








ALT 2 SOLN
public double averageInRange(int [] numbers, int low, int high)
{
   ArrayList<Integer> elements = new ArrayList<Integer>();
   for (int value: numbers)
   {    
      if (value >= low && value <= high)
      {  
         elements.add(value);
      }  
   }   

   double average = 0; 
   for (int value: elements)
   {
       average += value;
   }

   return average/element.size(); 
}              




3. 
public ArrayList<String> findNames(ArrayList<String> birthdates, int year)
{                 
   ArrayList<String> answers = new ArrayList<String>();                   
                     
   for(String str: birthdates)                
   {              
      int birthyear =
       Integer.parseInt(str.substring(str.indexOf(",")+2));              
       String name = str.substring(0,str.indexOf(":"));                   
       if (year == birthyear)                  
       {                        
          answers.add(name);           
       }                        
   }              
   return answers;              
}       



ALT SOLN:
public ArrayList<String> findNames(ArrayList<String> birthdates, int year)
{                 
   ArrayList<String> answers = new ArrayList<String>();                   
   Syear = year + "";
                     
   for(String str: birthdates)                
   {              
       String birthyear = str.substring(str.indexOf(",")+2);              
       String name = str.substring(0,str.indexOf(":"));                   
       if (Syear.equals(birthyear))                  
       {                        
          answers.add(name);           
       }                        
   }              
   return answers;              
}       










ALT 2 SOLN
public ArrayList<String> findNames(ArrayList<String> birthdates, int year)
{                 
   ArrayList<String> answers = new ArrayList<String>();                   
                     
   for(int k=0; k< birthdates.size(); k++)                
   {              
      String str = birthdates.get(k); 
      int birthyear =
       Integer.parseInt(str.substring(str.indexOf(",")+2));              
       String name = str.substring(0,str.indexOf(":"));                   
       if (year == birthyear)                  
       {                        
          answers.add(name);           
       }                        
   }              
   return answers;              
}       

ALT 3 SOLN   (convert strings to scanners)

public ArrayList<String> findNames(ArrayList<String> birthdates, int year)
{                 
   ArrayList<String> answers = new ArrayList<String>();                   
                     
   for(String str: birthdates)                
   {   
       // convert string into a scanner
       Scanner input = new Scanner(str);
       
       String name = ""; 
       while (input.hasNext() && name.length > 0 && 
                name.charAt[name.length-1] != ":")
       {
             name += " " + input.next();
       }
       if (name.charAT[name.length-1] == ":")
       {
            name = name.substring(0,name.length()-1);
       }
       // get the year
       input.next();  // ignore the month
       input.next();  // ignore the day,
       int birthyear = input.nextInt();

       if (birthyear == year)
       {                        
          answers.add(name);           
       }                        
   }              
   return answers;              
}       



4. PART A. 
public SkiJumper(String name, double jump)                  
{                 
   myName = name;               
   myCurrentJump = 0;                         
   myBestJump = jump;                         
}

public String getName()                       
{                 
   return myName;               
}
                     
public double getCurrentJump()                
{                 
  return myCurrentJump;                      
}

public double getBestJump()                   
{                 
   return myBestJump;                         
}                 
                     
public void setCurrentJump(double jump)                     
{                 
   myCurrentJump = jump;                      
   if (myCurrentJump > myBestJump)            
   {              
      myBestJump = myCurrentJump;             
   }              
}  

PART B. 
public void competition(Scanner in)          
{                
    // read in first two lines and create two SkiJumpers. 
    SkiJumper skierOne = new SkiJumper(in.next() + " " + in.next(),
    in.nextDouble());                 
    SkiJumper skierTwo = new SkiJumper(in.next() + " " + in.next(),
    in.nextDouble());                 
                   
    // process the rest of the file 
    while(in.hasNext())                       
    {                           
       String name = in.next() + " " + in.next();           
                   
       if (name.equals(skierOne.getName()))                 
       {                        
          skierOne.setCurrentJump(in.nextDouble());         
       }                        
       else
       {                        
          skierTwo.setCurrentJump(in.nextDouble());         
       }                        
    }                           
                    
    System.out.println(skierOne.getName() + "'s longest jump was " +      
          skierOne.getBestJump());            
    System.out.println(skierTwo.getName() + "'s longest jump was " +      
          skierTwo.getBestJump());            
                  
    // print a message stating who jumped further           
    if (skierOne.getBestJump() > skierTwo.getBestJump())  
    {                           
       System.out.println(skierOne.getName() + " jumped further");        
    }                           
    else if (skierTwo.getBestJump() > skierOne.getBestJump())             
    {                           
       System.out.println(skierTwo.getName() + " jumped further");        
    }                           
    else                        
    {                           
       System.out.println("They jumped the same distance");               
    }                           
}