CMP211 Problems

For Classes of David B. Sher

·         Array Manipulation

    1. Write a method that returns the largest number in its parameter, an array of floats.
    2. Write a method that takes a parameter that is an array of floats and a float parameter that is the limit. If any element of the array is greater than the limit then the method returns true otherwise it returns false.
    3. Write a method that returns true if a String parameter contains the letter A.
    4. Write a method that counts how many c’s are in a String parameter (and returns the count).
    5. Write a method that returns the first letter in a String that is a capitol letter.  If there is no such letter it should throw an Exception. 

·         Style Problems

    1. Comment this method:


public static float calculate(int x, float y)
{

float twice_x = 2.0*x;
float three_y = 3.0*y;
if(twice_x > three_y) return twice_x;
else return three_y;

}

    1. Which of these names are good method names and why


xxx, standardDeviation, z3, return, doesIt, retrieveNews, Product

1.      Write a class that implements this interface:
public interface Lesson
{
            /** returns first string in lesson */
            public String first ();
            /** returns last string in lesson */
            public String last ();
            /** returns true if all strings are equal */
            public boolean allSame();
            /** replaces first string with parameter */
            public void setFirst(String first);
            /** replaces last string with parameter */
            public void setLast(String last);
} // end lesson

2.      Write a method that has two Lesson parameters that returns true if all the strings in both Lessons are equal.

3.      Write a class that has two Lesson instance variables.  It should have methods to set and get the two lessons.  It should also have a method that returns true if both Lessons have equal first strings. 

·         Stack Problems

    1. Write accessors of an implementation of the stack interface that return:
      1. The number of elements of the stack that are equal to the top element
      2. True if all the elements of the stack are = and false otherwise.
      3. The first element of the stack that is equal to the parameter.
      4. The largest of the elements of the stack.
      5. True if the stack has some elements larger than its parameter, False otherwise.
      6. True if the stack's elements are all larger than the parameter, False otherwise.
      7. The number of elements in the stack larger than the parameter.

·         Unsorted List Problems

    1. Write modifiers of the implementation of the list interface that:
      1. Delete the nth element of the list (n is a parameter of the member).
      2. Delete the first element of the list that is larger than the parameter of the member.
      3. Insert the first parameter before the first element that is larger than second parameter of the member.
      4. Delete all the elements of the list that are larger than the parameter of the member.

·         Queue (Wrap around) Problems

    1. Write accessors of an implementation of the queue interface using the wrap around technique that return:
      1. The number of elements of the queue that are equal to the top element
      2. True if all the elements of the queue are = and false otherwise.
      3. The first element of the queue that is equal to the parameter.
      4. The largest of the elements of the queue.
      5. True if the queue has some elements larger than its parameter, False otherwise.
      6. True if the queue’s elements are all larger than the parameter, False otherwise.
      7. The number of elements in the queue larger than the parameter.

·         Sorting Problems

    1. How can you efficiently modify the selection sort algorithm to find the 5 largest elements in the list?  Can you modify insert sort to do the same thing?
    2. Change bubble sort to find the n largest elements of a list (n is a parameter).

·         Linked Stack Problems

    1. Write accessors of a linked list implementation of the stack interface that returns:
      1. The number of elements of the stack that are equal to the top element
      2. True if all the elements of the stack are = and false otherwise.
      3. The first element of the stack that is equal to the parameter.
      4. The largest of the elements of the stack.
      5. True if the stack has some elements larger than its parameter, False otherwise.
      6. True if the stack's elements are all larger than the parameter, False otherwise.
      7. The number of elements in the stack larger than the parameter.

·         Linked List Problems

    1. Write modifiers of a linked list implementation of the list interface that:
      1. Delete the nth element of the list (n is a parameter of the member).
      2. Delete the first element of the list that is larger than the parameter of the member.
      3. Insert the first parameter before the first element that is larger than second parameter of the member.
      4. Delete all the elements of the list that are larger than the parameter of the member.

·         Circularly Linked Queue Problems

    1. Write accessors of the circularly linked implementation of the queue interface that return:
      1. The number of elements of the queue that are equal to the top element
      2. True if all the elements of the queue are = and false otherwise.
      3. The first element of the queue that is equal to the parameter.
      4. The largest of the elements of the queue.
      5. True if the queue has some elements larger than its parameter, False otherwise.
      6. True if the queue’s elements are all larger than the parameter, False otherwise.
      7. The number of elements in the queue larger than the parameter.

 

·         Recursive Method Problems

1.        public static int recurse(int x) { if(x<=1) return x; else return recurse(x-1)+2*recurse(x-2); }
what is recurse (1), recurse(2), recurse(4), recurse(8)?

2.        public static int recurse2(int y) { if(y <= 2)  return y+3; else return recurse(y-1)+recurse(y/2);
what is recurse (1), recurse(2), recurse(5), recurse(10)?

3.        Write a member method  of recursive list type that returns the sum of all the items in a list that are > than its parameter?

·         Tree Problems

1.      Output the characters of this tree in prefix, postfix and infix.

2.      Write a method that returns the product of items in a tree.

·         Recursive Searching Problem

1021
2102
2011
1102
2011
1122
1212
2012

1.                  Show the list after each merge of merge sort.

2.                  Show the list after each split and each merge of quick sort