CS35: Quiz 3 Study Guide

In addition to all concepts from Quiz 1, and Quiz 2

You should be able to define or explain the following terms:

You should be familiar with the following C++-related concepts:

Practice problems

  1. For each data structure covered in the course, come up with a real-world application that motivates the data structure. The data structure should be able to provide a more efficient solution to the problem then any other structure covered so far.

  2. Give a binary tree with integer keys at nodes, whose traversals are:
    • PreOrder: [80 46 92 90 121 111 105]
    • InOrder: [46 80 90 92 105 111 121]
    • PostOrder: [46 90 105 111 121 92 80]
    Is the tree a BST? Is it an AVLTree? Justify your response.

  3. Consider the following tree:
    1. What is the pre-order traversal of the tree?
    2. What is the in-order traversal of the tree?
    3. What is the post-order traversal of the tree?
    4. What is the level-order traversal of the tree?
    5. Identify if it is a tree, binary tree, BST, AVL tree
    6. Based on your previous answer, draw the tree obtained by inserting 10 into the tree.
    7. Draw the tree obtained by deleting 2 from the tree.
    8. Draw both trees that might be obtained by deleting 4 from the tree while still maintaining the properties in your answer to e)

  4. Consider a boolean function LinkedBST::containsInRange that takes as arguments two keys -- min and max -- and returns true if there exists a key k in the tree such that min <= k <= max. One possible implementation of this function is to call a recursive helper function that takes an additional argument -- a node in the tree, and returns whether that subtree contains any keys in the range:
      template <typename K, typename V>
      bool LinkedBST<K,V>::containsInRange(K min, K max) {
        return subtreeContainsInRange(root, min, max);
      }
    
    Write the recursive helper function subtreeContainsInRange. You may assume that empty trees are represented by pointer to a NULL node.

  5. For each of the code fragments below, draw the AVLTree that results from the code fragment:
    1.   AVLTree<int,int> t;
        for (int i = 1; i <= 10; ++i) {
          t.insert(i,i);
        }
      
    2.   AVLTree<int,int> t;
        for (int i = 1; i <= 5; ++i) {
          t.insert(i,i);
          t.insert(-1*i,-1*i);
        }
      
    3.   AVLTree<int,int> t;
        for (int i = 1; i <= 5; ++i) {
          t.insert(i,i);
          t.insert(11-i,11-i);
        }
      

  6. For each of the three code fragments above, draw the tree that would result if a LinkedBST were used instead of an AVLTree.

  7. What is the worst-case running time of the following function? Use Big-O notation.
      void f(int n) {
        if (n < 0) {
          return;
        }
        AVLTree<int,int> t;
        for (int i = 0; i < n; ++i) {
          t.insert(i,i);
        }
        for (int i = 0; i < n; ++i) {
          cout << t.remove(i) << endl;
        }
      }
    

  8. What is the smallest AVL tree such that removing a node requires a rotation to rebalance the tree? (There is more than one correct answer, but they're all the same size.)

  9. What is the smallest AVL tree such that removing a node requires two rotations to rebalance the tree? (Again there is more than one correct answer, but they're all the same size.)

  10. For each of the code fragments below, draw the BinaryHeap that results from the code fragment, and draw its final array-based representation:
    1.   BinaryHeap<int,int> heap;
        for (int i = 1; i <= 10; ++i) {
          heap.insert(i,i);
        }
        for (int i = 1; i <= 5; ++i) {
          heap.removeMin();
        }
      
    2.   BinaryHeap<int,int> heap;
        for (int i = 10; i > 0; --i) {
          heap.insert(i,i);
        }
      
    3.   BinaryHeap<int,int> heap;
        for (int i = 1; i <= 5; ++i) {
          heap.insert(i,i);
          heap.insert(-1*i,-1*i);
        }
      
  11. What is the worst-case running time of the following function? Use Big-O notation.
      void f(int n) {
        if (n < 0) {
          return;
        }
        BinaryHeap<int,int> heap;
        for (int i = 0; i < n; ++i) {
          heap.insert(i,i);
        }
        for (int i = 0; i < n; ++i) {
          cout << heap.removeMin() << endl;
        }
      }