Balance calculation algorithm in LLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to initialize the balance variable correctly.

LLD

balance = [1]

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

A0

BNone

C''

D-1

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing balance as None causes errors when adding amounts.

Using a negative number as initial balance is incorrect.

The balance should start at zero to correctly accumulate transactions.

2fill in blank

medium

Complete the code to add a transaction amount to the balance.

LLD

balance = balance [1] transaction_amount

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

A/

B+

C*

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using subtraction instead of addition reduces the balance incorrectly.

Using multiplication or division is not appropriate here.

Adding the transaction amount updates the balance correctly.

3fill in blank

hard

Fix the error in the condition to check if the balance is negative.

LLD

if balance [1] 0:
    print('Balance is negative')

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

A>

B==

C<

D>=

Attempts:

3 left

💡 Hint

Common Mistakes

Using greater than or equal to checks for positive or zero balances.

Using equality checks only for zero balance.

The balance is negative if it is less than zero.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension that maps account IDs to their balances if balance is positive.

LLD

positive_balances = {account_id: [1] for account_id, [2] in accounts.items() if balance > 0}

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

Abalance

Caccount_balance

Damount

Attempts:

3 left

💡 Hint

Common Mistakes

Using different variable names causes errors or undefined variables.

Not matching the variable in the condition with the loop variable.

The dictionary comprehension uses 'balance' as the value and 'account_balance' as the variable name for balances.

5fill in blank

hard

Fill all three blanks to create a function that calculates the total balance from a list of transactions.

LLD

def calculate_total_balance(transactions):
    total = [1]
    for [2] in transactions:
        total [3]= transaction
    return total

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

A0

Btransaction

C+

Dbalance

Attempts:

3 left

💡 Hint

Common Mistakes

Initializing total to None or other types causes errors.

Using incorrect loop variable names or operators.

The function initializes total to zero, iterates over each transaction, adds it to total, and returns the total balance.