How should I practice Stacked Item and Category Discounts?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Palantir online assessment problems in FastPrep.

Is Stacked Item and Category Discounts associated with Palantir?

FastPrep tags this as a Palantir online assessment coding practice problem when the problem catalog has that company and stage context.

Stacked Item and Category Discounts

Palantir● MediumNEW GRADOA

Learn

Problem statement

You are given a shopping cart and item-specific or category-wide percentage discounts. Each cart item has a name, an integer-cent price, and a category. Each discount has type item or category, a matching name, and a percentage.

For each item, apply its matching item discount first and its matching category discount second. The two discounts stack multiplicatively. For example, 10% off followed by 20% off leaves price * 0.90 * 0.80, so the total discount is 28%.

The total discount on one item cannot exceed 80% of its original price. If the next discount would exceed that limit, apply only enough of it to reach exactly 80%. Ignore unmatched discounts.

Return a three-element array containing the subtotal, total rounded discount, and final total. Compute each item's combined discount without intermediate rounding, cap it at 80%, and then round that final discount to the nearest cent. An exact half-cent tie rounds to the nearest even integer.

Function

calculateStackedDiscountTotals(itemNames: String[], prices: int[], categories: String[], discountTypes: String[], discountNames: String[], percentOff: int[]) → long[]

Examples

Example 1

itemNames = ["Milk"]prices = [500]categories = ["Dairy"]discountTypes = ["item", "category"]discountNames = ["Milk", "Dairy"]percentOff = [10, 20]return = [500, 140, 360]

The stacked price factor is 0.90 * 0.80 = 0.72, so the discount is 140 cents.

Example 2

itemNames = ["Laptop"]prices = [1000]categories = ["Electronics"]discountTypes = ["item", "category"]discountNames = ["Laptop", "Electronics"]percentOff = [70, 50]return = [1000, 800, 200]

The discounts would save 85%, so the per-item cap limits the discount to 800 cents.

Example 3

itemNames = ["A"]prices = [105]categories = ["X"]discountTypes = ["item"]discountNames = ["A"]percentOff = [10]return = [105, 10, 95]

The raw 10.5-cent discount is an exact tie and rounds to the even value 10.

Constraints

1 ≤ itemNames.length = prices.length = categories.length ≤ 100000.
0 ≤ discountTypes.length = discountNames.length = percentOff.length ≤ 100000.
0 ≤ prices[i] ≤ 10^9.
0 ≤ percentOff[i] ≤ 100.
Every discount type is exactly item or category.
There is at most one item discount per item name and at most one category discount per category.
Names and categories are non-empty case-sensitive strings.
The subtotal and returned totals fit in a signed 64-bit integer.