Collision handling (chaining) in Data Structures Theory - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize an empty hash table with chaining.

Data Structures Theory

hash_table = [[] for _ in [1]]

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Alist

B10

Cdict

Drange(10)

Attempts:

3 left

💡 Hint

Common Mistakes

Using an integer directly instead of a range.

Using list or dict which are types, not ranges.

We use range(10) to create 10 empty lists, one for each bucket in the hash table.

2fill in blank

medium

Complete the code to compute the hash index for a key in a hash table of size 10.

Data Structures Theory

index = hash(key) [1] 10

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A+

B//

C%

D**

Attempts:

3 left

💡 Hint

Common Mistakes

Using division (//) which gives quotient, not remainder.

Using addition (+) which can exceed table size.

The modulo operator % ensures the index stays within the table size by wrapping around.

3fill in blank

hard

Fix the error in the code that inserts a key-value pair into the hash table using chaining.

Data Structures Theory

hash_table[index].[1]((key, value))

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Aadd

Bappend

Cinsert_at

Dput

Attempts:

3 left

💡 Hint

Common Mistakes

Using add which is for sets, not lists.

Using non-existent methods like insert_at or put.

We use append to add the key-value pair to the list at the computed index.

4fill in blank

hard

Fill both blanks to complete the code that searches for a key in the hash table using chaining.

Data Structures Theory

for k, v in hash_table[[1]]:
    if k [2] key:
        return v

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Aindex

B==

C!=

Dkey

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong comparison operator like !=.

Using a variable name instead of the index for the bucket.

We look in the bucket at index and check if any key k equals the searched key.

5fill in blank

hard

Fill all three blanks to complete the code that deletes a key-value pair from the hash table using chaining.

Data Structures Theory

bucket = hash_table[[1]]
for i, (k, v) in enumerate(bucket):
    if k [2] key:
        del bucket[[3]]
        break

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Aindex

B==

Ci

Dkey

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong operator like !=.

Deleting by key instead of index.

Using wrong variable names.

We find the bucket at index, check if k == key, then delete the item at position i.