Split strategies (equal, exact, percentage) in LLD - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to split the total amount equally among all participants.

LLD

share = total_amount [1] number_of_participants

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

A*

B+

C/

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using multiplication instead of division.

Using addition or subtraction which does not split the amount.

To split equally, divide the total amount by the number of participants.

2fill in blank

medium

Complete the code to assign an exact amount to a participant.

LLD

participant_share = [1]

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

Aexact_amount

Btotal_amount / number_of_participants

Cpercentage * total_amount

Dtotal_amount - exact_amount

Attempts:

3 left

💡 Hint

Common Mistakes

Using division or percentage calculations instead of fixed amount.

Subtracting amounts which is incorrect here.

Exact split means assigning a fixed amount directly.

3fill in blank

hard

Fix the error in the code to calculate participant share by percentage.

LLD

participant_share = total_amount [1] percentage

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

A*

B/

C+

D-

Attempts:

3 left

💡 Hint

Common Mistakes

Using division or addition instead of multiplication.

Using subtraction which reduces the amount incorrectly.

To calculate share by percentage, multiply total amount by the percentage.

4fill in blank

hard

Fill both blanks to create a dictionary comprehension for exact splits.

LLD

splits = {participant: [1] for participant, [2] in exact_amounts.items()}

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

Aamount

Bshare

Cexact_amount

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using incorrect variable names that do not match the dictionary items.

Confusing keys and values in the comprehension.

Use 'value' as the value and the variable from items() for clarity.

5fill in blank

hard

Fill all three blanks to calculate percentage splits and store in a dictionary.

LLD

percentage_splits = {participant: total_amount [1] [2] for participant, [3] in percentages.items()}

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

A*

B/

Cpercentage

Dvalue

Attempts:

3 left

💡 Hint

Common Mistakes

Using division instead of multiplication.

Using wrong variable names for the percentage value.

Multiply total amount by the value (percentage) from the dictionary.

Practice

1. Which split strategy divides an amount so that everyone pays the same share regardless of individual preferences?

easy

A. Equal split

B. Exact split

C. Percentage split

D. Random split

Solution

1. Step 1: Understand the definition of equal split

   Equal split means dividing the total amount evenly among all participants.

2. Step 2: Compare with other splits

   Exact split assigns specific amounts, percentage split assigns based on percent, random split is not a standard method.

3. Final Answer:

   Equal split -> Option A

4. Quick Check:

   Equal split = same share for all [OK]

Hint: Equal split means everyone pays the same amount [OK]

Common Mistakes:

• Confusing exact split with equal split
• Thinking percentage split always equals equal split
• Assuming random split is a valid standard method

2. Which of the following is the correct syntax to represent a percentage split of 40% for user A and 60% for user B in a system design context?

easy

A. {'A': '40%', 'B': '60%'}

B. {'A': 40, 'B': 60}

C. {'A': 0.4, 'B': 0.6}

D. {'A': 4, 'B': 6}

Solution

1. Step 1: Understand percentage representation in decimals

   Percentages are often represented as decimals between 0 and 1 in code for calculations.

2. Step 2: Evaluate options

   {'A': 0.4, 'B': 0.6} uses decimals summing to 1, correct for percentage split. {'A': 40, 'B': 60} uses integers but not decimals. {'A': '40%', 'B': '60%'} uses strings which are not directly usable. {'A': 4, 'B': 6} uses incorrect smaller numbers.

3. Final Answer:

   {'A': 0.4, 'B': 0.6} -> Option C

4. Quick Check:

   Decimal form for percentages = {'A': 0.4, 'B': 0.6} [OK]

Hint: Use decimals (0.4) not integers (40) for percentage splits [OK]

Common Mistakes:

• Using integers instead of decimals for percentages
• Using strings with % symbol in code
• Not ensuring sum equals 1

3. Given a total amount of 100 and a split strategy: {'A': 30, 'B': 70} as exact amounts, what is the amount assigned to user B?

medium

A. 70

B. 100

C. 30

D. 0

Solution

1. Step 1: Identify the split type and amounts

   The split is exact, so amounts are assigned directly as given.

2. Step 2: Find user B's assigned amount

   User B is assigned 70 as per the exact split dictionary.

3. Final Answer:

   70 -> Option A

4. Quick Check:

   Exact split assigns given amounts = 70 [OK]

Hint: Exact split means use given amounts directly [OK]

Common Mistakes:

• Adding amounts instead of reading assigned value
• Confusing exact with percentage split
• Assuming equal split when exact is given

4. In a percentage split system, if the sum of percentages provided is 110%, what is the main issue and how should it be fixed?

medium

A. The sum is valid, no fix needed

B. The sum should be exactly 0%, reset all percentages

C. The sum is less than 100%, add missing percentage

D. The sum exceeds 100%, fix by normalizing percentages to sum to 100%

Solution

1. Step 1: Identify the problem with sum of percentages

   Percentages must sum to 100% (or 1 in decimal) to correctly split amounts.

2. Step 2: Determine the fix

   If sum is 110%, it exceeds total amount. Normalize by scaling percentages so they sum to 100%.

3. Final Answer:

   The sum exceeds 100%, fix by normalizing percentages to sum to 100% -> Option D

4. Quick Check:

   Sum > 100% requires normalization [OK]

Hint: Percentages must sum to 100%, else normalize [OK]

Common Mistakes:

• Ignoring sum validation
• Assuming sum can be more than 100%
• Trying to add missing percentage when sum is too high

5. You need to design a system that supports splitting a bill among users using equal, exact, or percentage strategies. Which approach best ensures scalability and correctness when handling thousands of users?

hard

A. Allow users to input any split without checks and calculate on demand

B. Use a unified split interface that validates input and applies the correct split logic per strategy

C. Store all splits as exact amounts without validation

D. Hardcode equal split only to simplify calculations

Solution

1. Step 1: Identify requirements for scalability and correctness

   System must handle many users and ensure splits are valid and consistent.

2. Step 2: Evaluate design approaches

   Unified interface with validation ensures correctness and flexibility. Hardcoding or no validation risks errors and poor scalability.

3. Final Answer:

   Use a unified split interface that validates input and applies the correct split logic per strategy -> Option B

4. Quick Check:

   Unified validated interface = scalable & correct [OK]

Hint: Validate splits and use unified logic for scalability [OK]

Common Mistakes:

• Ignoring validation leading to incorrect splits
• Hardcoding one strategy limits flexibility
• Allowing unchecked input causes errors at scale