CSE 310 Quizzes with correct answers.

CSE 310 Quizzes with correct answers
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What is the height of any binary search tree with n nodes? -
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CORRECT ANSWERS ✔✔O(log n) |\ |\ |\




Consider the hashing function h(k) = k mod m.
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What is a good value for m? - CORRECT ANSWERS ✔✔A prime
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number.


Which of the following statements are true regarding direct
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address tables? |\




Statement 1: If the universe U is large, storing a table of size |U|
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may be impractical.
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Statement 2: Often, most of the space allocated to table T is
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wasted as the set K of keys actually stored is small. - CORRECT
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ANSWERS ✔✔Both of the statements are true. |\ |\ |\ |\ |\ |\ |\




Storing a large table is impractical because one will be allocating
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a large table, where here may be collisions or often times,
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unused space. |\




If for example, the set is [1 8 10 12 20], one may allocate
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memory of size 20 and store each at value - 1, there will be 20
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spaces allocated for only 5 elements, leaving 15 spaces unused.
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,What is a hash table? - CORRECT ANSWERS ✔✔A generalization
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of an ordinary array where a function of key is used as the index
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instead of using key as index directly. |\ |\ |\ |\ |\ |\




Keys 5, 4, 6, 1, 2 are mapped to a hash table of size 3 with hash
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function h(k) = k mod 3. If collisions are resolved by separate
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chaining, what are the values of a, b, c, d, e respectively as
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shown below? |\




T
0 -> a -> /
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1 -> b -> c -> /
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2 -> d -> e -> / - CORRECT ANSWERS ✔✔6, 4, 1, 5, 2
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Insert keys 7, 10, 25, 12, 17, 34 into a hash table of size 7 using
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open addressing, with the hash function h(k, i) = (k + i) mod 7
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and linear probing to resolve collisions. What does the final array
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look like? - CORRECT ANSWERS ✔✔[7, 34, EMPTY, 10, 25, 12, 17]
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What is true about hash tables? - CORRECT ANSWERS
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✔✔Collisions can happen even when |K| <= m where K is the |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\


number of keys and m is the size of hash table.
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Deleting a key from hash table is O(1) if collisions are resolved by
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chaining and if the lists are doubly linked.
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, Which of the following statements are true?
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Statement 1: With a different interpretation, hash functions can
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be used even when the keys are strings.
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Statement 2: Hash functions should be fast, i.e, O(1) to compute.
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- CORRECT ANSWERS ✔✔Both statements are true.
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What is a collision? - CORRECT ANSWERS ✔✔When two keys hash
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to the same value?
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Considering the case of separate chaining in hashing. Which of
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the following are true?
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Statement 1: Performance of the dictionary operations is not
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good because of the use of a linked list.
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Statement 2: The chain is not maintained in sorted order. -
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CORRECT ANSWERS ✔✔Both statements are true. |\ |\ |\ |\ |\




The use of a linked list has little effect towards the performance
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of dictionary operations.
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The element is simply inserted at the end of the chain,
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regardless of order. |\ |\