CS-301 Data Structure. Tariq Hanif

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1 1. The tree data structure is a Linear data structure Non-linear data structure Graphical data structure Data structure like queue FINALTERM EXAMINATION Spring 2012 CS301- Data Structure In the linked list implementation of the queue class, where does the insert member function place the new entry on the linked list? At the head At the tail After all other entries that are greater than the new entry. After all other entries that are smaller than the new entry 3.The operation for removing an entry from a stack is traditionally called: delete peek pop remove 4.A binary tree with N internal nodes has links, links to internal nodes and links to external nodes 2N, N-1, N+1 Page 315 N-1, 2N, N+1 N+1, N-1, 2N N+1, N-1, 2N 5.If there are N elements in an array then the number of maximum steps needed to find an element using Binary Search is. N N 2 N 2 log 2 N 6.A binary tree with 45 internal nodes has links to external nodes

2 7.Suppose that a selection sort of 100 items has completed 42 iterations of the main loop. How many items are now guaranteed to be in their final spot Which one of the following algorithms is least efficient, Quick Sort Insertion Sort Merge Sort Bubble Sort 9.A binary tree with 33 internal nodes has links to internal nodes The maximum number of external nodes (leaves) for a binary tree of height H is 2 H 2 H +1 2 H -1 2 H A complete binary tree of height has nodes between 16 to The worst case of building a heap of N keys is N N 2 Nlog2N 363 NlogN 2 N 13. Suppose we had a hash table whose hash function is n % 12, if the number 35 is already in the hash table, which of the following numbers would cause a collision? A binary tree with 24 internal nodes has external nodes

3 15- is a c data structure that can grow easily dynamically at run time without having to copy existing elements. Array List Two dimensional array Linked list 16.Whenever we write a class it begins with, Class body Class declaration Class name Class constructor 17. Which one of the following is TRUE about recursion? Recursion extensively uses stack memory. 149 Threaded Binary Trees use the concept of recursion. Recursive function calls consume a lot of memory. Recursive function calls consume a lot of memory. 18. If we insert a new node in an AVL tree which is perfectly balanced tree, then we will need to keep it AVL. One rotation Two rotations Rotations equal to number of levels No rotation at all 19. The worst case of deletion in AVL tree requires. Only one rotation Rotation at each non-leaf node Rotation at each leaf node Rotations equal to log 2 N 20. In Threaded Binary Tree, every node that does not have a right-child has a thread to its In-order predecessor Pre-order successor In-order successor Pre-order predecessor 21-In the Disjoint sets, union is a time operation. Constant Variable Exponential Quadratic 22. Merge sort and quick sort both fall into the same category of sorting algorithms, which is known as: O (NlogN) sorts Interchange sorts Quadratic average time sorts Complex sorts

4 23-In an array list, the worst case of removing an element is : To remove an element from the end of the list 16 To remove an element from the start of the list We cannot remove element from an array list To remove an element from the middle of the list 24. Which one of the following is NOT true about transient object? The lifetime of a transient object can exceed that of the application which is accessing it. An instance of an object type. Its lifetime cannot exceed that of the application. Not sure Application can also delete a transient object at any time. 25.In case of deleting a node from AVL tree, rotation could prolong to the... node. Leaf Root Middle node Sibling 26- Left pointer of dummy node in a threaded binary tree points to Itself while the right pointer points to the root of tree. Root node of the tree while the right pointer points itself Root node of the tree while the right pointer is always NULL. NULL while the right pointer of dummy node points to the itself. 27. In threaded Binary tree, we convert pointers of the tree to threads. Left Right Null 323 all 28. Which one of the following is NOT true regarding the skip list? Each list S i contains the special keys + infinity and - infinity. List S 0 contains the keys of S in non-decreasing order. Each list is a subsequence of the previous one. List S h contains only the n special keys. 29.The definition of Transitivity property is For all element x member of S, x R x For all elements x and y, x R y if and only if y R x For all elements x, y and z, if x R y and y R z then x R z For all elements w, x, y and z, if x R y and w R z then x R z.30.which one of the following is NOT an example of equivalence relation: Electrical connectivity Set of people <= relation Set of pixels 31.A find(x) on element x is performed by : returning exactly the same node that is found. returning the root of the tree containing x. returning the whole tree itself containing x. returning "true".

5 32.A simple sorting algorithm like selection sort or bubble sort has a worst-case of O(1) time because all lists take the same amount of time to sort O(n) time because it has to perform n swaps to order the list. O(n 2 ) time because sorting 1 element takes O(n) time O(n 3 ) time, because the worst case has really random input which takes longer to sort 33.Suppose A is an array containing numbers in increasing order, but some numbers occur more than once. When using a binary search for a value, the binary search always finds the first occurrence of value. the second occurrence of value. may find first or second occurrence of value. It will give an error. 34.When unions are done by weight (size) and N=1000,000 where N is the number of nodes then what will be the maximum levels of tree? 1000, What is the best definition of collision in a hash table? Two entries are identical except for their keys Two entries with different data have different keys. Two entries with different keys have the same hash value. Two entries with the same key have different hash values. 36. Which of the following is NOT true regarding the maze generation? Randomly remove walls until the entrance and exit cells are in the same set. Removing a wall is the same as doing a union operation. Remove a randomly chosen wall if the cells it separates are already in the same set. Do not remove a randomly chosen wall if the cells it separates are already in the same set. 37. Which of the given option is NOT a factor in Union by Size: Maintain sizes (number of nodes) of all trees Make smaller tree, the subtree of the larger one. Make the larger tree, the subtree of the smaller one Maintain sizes (number of nodes) while performing union operation 38. While deleting a node from Binary Search Tree (BST), which of the following number of cases we have to take care of? Function Calls are made with the help of which of the following data structures? Hash Table Stack Binary Tree Queue

6 40.A binary relation R over S is called an equivalence relation if it has which of the following property/properties? Reflexivity Symmetry Transitivity Reflexivity, Symmetry and Transitivity 394 FINALTERM EXAMINATION Spring 2012 CS301- Data Structure Numbers 5, 222, 4, 48 are inserted in a queue, which one will be removed first? The tree data structure is a Linear data structure Non-linear data structure 112 Graphical data structure Data structure like queue 3. Suppose that the class declaration of SomeClass includes the following function prototype. bool LessThan( SomeClass anotherobject ); Which of the following tests in the client code correctly compares two class objects alpha and beta? if (alpha < beta) if (alpha.lessthan(beta)) if (LessThan(alpha, beta)) if (LessThan(alpha).beta)

7 4.If there are 56 internal nodes in a binary tree then how many external nodes this binary tree will have? A binary tree of N nodes has. Log 10 N levels Log 2 N levels 227 N / 2 levels N x 2 levels 6. Binary Search is an algorithm of searching, used with the data. Sorted 439 Unsorted Heterogeneous Random 7. If there are N elements in an array then the number of maximum steps needed to find an element using Binary Search is. N N 2 Nlog 2 N log 2 N

8 8. Consider to following array After the first pass of a particular algorithm, the array looks like Name the algorithm used Heap sort Selection sort Insertion sort Bubble sort according to rule 9. Which of the following statement is true about dummy node of threaded binary tree? This dummy node never has a value. This dummy node has always some dummy value. This dummy node has either no value or some dummy value. 231 This dummy node has always some integer value. 10. Which of the following statement is NOT true about threaded binary tree? Right thread of the right-most node points to the dummy node. Left thread of the left-most node points to the dummy node. The left pointer of dummy node points to the root node of the tree. Left thread of the right-most node points to the dummy node A complete binary tree is a tree that is filled, with the possible exception of the bottom level. Partially Completely 323 Incompletely Partly

9 12. Consider a min heap, represented by the following array: 10,30,20,70,40,50,80,60 After inserting a node with value 31.Which of the following is the updated min heap? 10,30,20,31,40,50,80,60, ,30,20,70,40,50,80,60,31 10, 31,20,30,40,50,80,60,31 31,10,30,20,70,40,50,80, Consider a min heap, represented by the following array: 11,22,33,44,55 After inserting a node with value 66.Which of the following is the updated min heap? 11,22,33,44,55, ,22,33,44,66,55 11,22,33,66,44,55 11,22,66,33,44, What requirement is placed on an array, so that binary search may be used to locate an entry? The array elements must form a heap. The array must have at least 2 entries. Array must be sorted The array s size must be a power of two. 15. We can not remove items randomly from Stack 431 Two dimensional arrays Array Linked list

10 16. + is a operator. Unary Binary 61 Ternary Unary and Binary 17. Huffman encoding uses to develop codes of varying lengths for the letters used in the original message. Linked list Stack Queue Binary tree Merge sort and quick sort both falls into the same category of sorting algorithms, which is known as: O (NlogN) sorts Interchange sorts Quadratic average time sorts Complex sorts 19. Suppose h is height of Binary Search Tree, then maximum steps required for a search operation are h H+1 2 h 2 h 1

11 20. Suppose currentnode refers to a node in a linked list (using the Node class with member variables called data and nextnode). Which statement changes currentnode so that it refers to the next node? currentnode ++ currentnode = nextnode; currentnode += nextnode; currentnode = currentnode->nextnode; 21. During insertion, there are cases for rotation in an AVL tree Which of the following can NOT be a max-heap? In min-heap, the node with minimum value is. Root 519 Left most child Right most child It can be anywhere in the heap. 24. While building Huffman encoding tree, the new node that is the result of joining two nodes has the frequency. Equal to the small frequency Equal to the greater frequency Equal to sum of the two frequencies 293

12 Equal to difference of the two frequencies 25. If there are 23 external nodes in a Binary tree, then number of internal nodes will be : If there are N internal nodes in a binary tree, then number of external nodes will be: N -1 N N N Which of the following is a property of Binary tree? A binary tree of N external nodes has N internal nodes. A binary tree of N internal nodes has N+1 external nodes. 303 A binary tree of N external nodes has N+1 internal nodes. A binary tree of N internal nodes has N-1 external nodes. 28. Which one of the following is NOT true regarding the skip list? Each list S i contains the special keys + infinity and - infinity. List S 0 contains the keys of S in non-decreasing order. Each list is a subsequence of the previous one. List S h contains only the n special keys. 446

13 29. Which one of the following is NOT the property of equivalence relation: Reflexive Symmetric Transitive Associative The definition of Transitivity property is For all element x member of S, x R x For all elements x and y, x R y if and only if y R x For all elements x, y and z, if x R y and y R z then x R z 385 For all elements w, x, y and z, if x R y and w R z then x R z 31. A find(x) on element x is performed by : returning exactly the same node that is found returning the root of the tree containing x. returning the whole tree itself containing x. returning "true". 32. A simple sorting algorithm like selection sort or bubble sort has a worst-case of O(1) time because all lists take the same amount of time to sort O(n) time because it has to perform n swaps to order the list. 2 O(n ) time because sorting 1 element takes O(n) time O(n 3 ) time, because the worst case has really random input which takes longer to sort. 33. Here is an array of ten integers: Array after the FIRST iteration of the main loop in selection sort algorithm will be (sorting from smallest to largest):

14 Suppose A is an array containing numbers in increasing order, but some numbers occur more than once. When using a binary search for a value, the binary search always finds the first occurrence of value. the second occurrence of value. may find first or second occurrence of value It will give an error. 35. When unions are done by weight (size), the depth of any element is never greater than log2n 420 nlog2n nlog2n+1 log2n When unions are done by weight (size) and N=1000,000 where N is the number of nodes then what will be the maximum levels of tree? 1000, What is the best definition of collision in a hash table? Two entries are identical except for their keys. Two entries with different data have different keys. Two entries with different keys have the same hash value. 471 Two entries with the same key have different hash values.

15 38. Suppose currentnode refers to a node in a linked list (using the Node class with member variables called data and nextnode). Which boolean expression will be true when CurrentNode refers to the tail node of the list? (currentnode == null) (currentnode->nextnode == null) (nextnode.data == null) (currentnode.data == 0.0) 39. Consider the following infix expression: x y * a + b / c Which of the following is a correct equivalent expression for the above? x y -a * b +c / x *y a - b c / + x y a * - b c / + x y a * - b/ + c 40. If we have 1,000 sets each containing a unique person, then which of the following relations would be true on each set? Reflexive Symmetric Transitive Associative