Data Structures Midterm

• What is an Array List?

  A dynamic data structure built on top of an array.
• How does resizing an Array List work?

  It creates a new underlying array and copies elements from the old one.
• What must all elements in an Array List have in common?

  All elements must be the same data type.
• What does the capacity of an Array List refer to?

  The maximum size of the underlying array.
• What are some examples of List declarations in C#?

  • List<decimal> monies;
  • List<byte[]> buffers;
  • List<List<List<int>>>
• What is the accuracy level of a Float data type?

  Close to accurate.
• How accurate is a Double compared to a Float?

  Twice as accurate as floats.
• When is the Decimal data type typically used?

  Often used for monetary values due to its high precision.
• What is the syntax for a basic For Loop in C#?

  for(int i=0; i<10; i++) { Console.WriteLine(i); }
• How can you modify a For Loop to step by 10?

  for(int i=0; i<10; i += 10) { Console.WriteLine(i); }
• What is the purpose of a For Each Loop?

  It avoids off-by-one errors when iterating through a collection.
• What is the basic operation of Bubble Sort?

  It compares an element with surrounding elements and moves the largest to the end.
• What is the runtime complexity of Bubble Sort?

  O(n²)
• How does Selection Sort operate?

  It finds the minimum element in the unsorted portion and swaps it with the first unsorted element.
• What is the runtime complexity of Selection Sort?

  O(n²)
• What does Insertion Sort do?

  It compares two elements and swaps them if they are not in order.
• Why is Insertion Sort considered the fastest among simple iterative sorts for small n?

  It efficiently sorts elements by building a sorted array one element at a time.
• How does Quick Sort function?

  It divides the array around a pivot and recursively sorts the sub-arrays.
• What is the runtime complexity of Quick Sort?

  O(n log n)
• How does Merge Sort operate?

  It divides the input array into two halves, sorts each half recursively, and merges them back together.
• What is the runtime complexity of Merge Sort?

  O(n log n)
• What are the types of testing in software development?

  • Unit Testing: Tests individual units (methods).
  • Integration Testing: Ensures compatibility between systems.
  • Performance Testing: Measures resource usage (CPU, memory, etc).
  • Acceptance Testing: Validates if the correct product was built.
• What does LIFO stand for in the context of a Stack?

  Last In First Out.
• What are the main operations of a Stack?

  Push, Pop, Peek.
• What does FIFO stand for in the context of a Queue?

  First In First Out.
• What are the main operations of a Queue?

  Enqueue, Dequeue, Peek.
• What is a Deque?

  A hybrid of stack and queue.
• What is a Singly Linked List?

  A linked list that contains a pointer to the next node.
• What is a Doubly Linked List?

  A linked list that contains pointers to both next and previous nodes.
• What is a Circular Linked List?

  A linked list where the last node points back to the head.
• What is the structure of a Circular Node in C#?

  Class CircularNode<T> { Public T data; Public CircularNode next; Public CircularNode prev; }
• How do you remove a node from a linked list?

  ToRemove.prev.next = ToRemove.next; ToRemove.next.prev = ToRemove.prev;
• What are the key characteristics of linked lists?

  • Singly Linked: Pointer to next node.
  • Doubly Linked: Pointers to next and previous nodes.
  • Circular Linked List: Last node points back to the head.
  • Circular Doubly Linked List: Combines both features.