Collision Handling Using Chaining in DSA Python - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the hash table with empty lists for chaining.

DSA Python

hash_table = [[] for _ in [1](10)]

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Adict

Blist

Cset

Drange

Attempts:

3 left

💡 Hint

Common Mistakes

Using dict() or set() instead of range() causes errors.

Using list() creates an empty list, not a range.

We use range(10) to create 10 empty lists for chaining in the hash table.

2fill in blank

medium

Complete the code to compute the hash index for a given key.

DSA Python

index = hash(key) [1] len(hash_table)

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A%

B+

C//

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using + or * can produce indexes outside the table range.

Using // gives the quotient, not the remainder.

We use modulo (%) to ensure the index fits within the hash table size.

3fill in blank

hard

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

DSA Python

def insert(hash_table, key, value):
    index = hash(key) % len(hash_table)
    for i, (k, v) in enumerate(hash_table[index]):
        if k == key:
            hash_table[index][i] = (key, [1])
            return
    hash_table[index].append((key, value))

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Akey

Bvalue

Cindex

Dhash_table

Attempts:

3 left

💡 Hint

Common Mistakes

Replacing with key instead of value loses the actual data.

Using index or hash_table as value causes errors.

We update the value for the existing key, so we replace with (key, value).

4fill in blank

hard

Fill both blanks to complete the search function that returns the value for a given key or None if not found.

DSA Python

def search(hash_table, key):
    index = hash(key) [1] len(hash_table)
    for k, v in hash_table[[2]]:
        if k == key:
            return v
    return None

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A%

B+

Cindex

Dkey

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of % causes index errors.

Using key instead of index to access the bucket causes runtime errors.

We use modulo (%) to get the index, then look in hash_table[index] for the key.

5fill in blank

hard

Fill all three blanks to complete the delete function that removes a key-value pair from the hash table.

DSA Python

def delete(hash_table, key):
    index = hash(key) [1] len(hash_table)
    for i, (k, v) in enumerate(hash_table[[2]]):
        if k == [3]:
            del hash_table[index][i]
            return True
    return False

Drag options to blanks, or click blank then click option'

A%

B+

Ckey

Dindex

Attempts:

3 left

💡 Hint

Common Mistakes

Using + instead of % causes wrong index.

Using key instead of index to access bucket causes errors.

Comparing k to index instead of key causes logic errors.

We compute index with %, access bucket with index, and compare k to key to delete.