Practice: Hashing

If we do the insertions in the order of the code snippet below, what is the resulting hash table? Assume the following:

• The hash table has 4 slots

• If there is a collision, add the new value at front of the chain

• We are using the hash function: h(v) = v % 4

nums = set()
nums.add(11)
nums.add(43)
nums.add(21)

Question 0

Your Task

Select one option. Write your answer down in your own space.

Option 0

Option 1

Option 2

Option 3

Option 4

None of the above

Question 1

Now for the hash table you have selected above, what should the return value be for the following call:

11 in nums

Your Task

Write your answer down in your own space.

Question 2

Now for the hash table you have selected above, what should the return value be for the following call:

5 in nums

Your Task

Write your answer down in your own space.

Question 3

Consider the class definition for a Dog class below. Which of the following implementations of __hash__ is the best, in the sense that it is functional and does the best job at meeting the properties of a good hash function

class Dog:

    def __init__(self, name, age):
        self._name = name
        self._age = age

    def __eq__(self, other):
        return self._name == other._name

Your Task

Select one option. Write your answer down in your own space.

Option 0

def __hash__(self):
    return hash(self._name)

Option 1

def __hash__(self):
    return 0

Option 2

Assume random is a function that generates a random number.

def __hash__(self):
    return hash(self._name) + random()

Option 3

def __hash__(self):
    return hash(self._name) + hash(self._age)