國立暨南國際大學 103 學年度第一學期小考試卷

1. (10%) Determine whether the following code is correct or not.  If it is correct, predict its output.  If it is incorrect, point out the mistake(s).
   
   class Point:
       def __init__(self,x,y) :   # Constructor
           self.x=x
           self.y=y
       def __str__(self):
           return "({0},{1})".format(self.x,self.y)
   
   def main():
       aList = [1, 3, 5, 7, 2, 4, 6]
       bList = [2, 4, 6, 1, 3, 5, 7]
       pList = []
       for x in aList:
           pList.append( Point(x, bList[aList.index(x)]) )
           # P.345
       for p in pList:
           print(p)
   
   main()
   
   
   
2. (10%) Determine whether the following code is correct or not.  If it is correct, predict its output.  If it is incorrect, point out the mistake(s).
   
   class Point:
       def __init__(self,x,y) :
           self.x=x
           self.y=y
       def distance(self) :
           r=(self.x**2+self.y**2)**(1/2)
           return r
       def __str__(self):
           return "({0},{1})".format(self.x,self.y)
   
   def main():
       aList = [ Point(1,2), Point(2,7), Point(3,4), Point(12,5), Point(6,8) ]
       aList.sort(key=Point.x)  
       # Sort by the X coordinate (pp.353--354)
       print(aList)
   
   main()
   
   
   
   
3. (10%) Determine whether the following code is correct or not.  If it is correct, predict its output.  If it is incorrect, point out the mistake(s).
   
   # Key Function for Sorting
   class Student:
       def __init__(self, n, id):
           self.name = n
           self.id = id
       def __str__(self):
           return self.id + ':' + self.name
       def get_id(self):
           return self.id
       def get_name(self):
           return self.name
   
   def get_name(aStudent):
       return 150 - ord(aStudent.name[0])
   
   def main():
       aList = [ Student("Alice", "177"),
           Student("Bob", "115"),
           Student("Carol", "135"),
           Student("Dickens", "193"),
           Student("Emily", "117") ]
       aList.sort(key=get_name)
       for p in aList:
           print(p)
   
   main()