How should I practice Product Total With the Cheapest Promotion?

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Problem · Array

Product Total With the Cheapest Promotion

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Problem statement

Given product and promotion records, return the minimum total price in integer cents.

Each product record has the form sku|name|quantity|priceCents. Skip a product record exactly when quantity or priceCents is negative, and continue processing later records. Every other record contributes independently, including repeated SKUs.

Promotion records have either form:

sku|pct|p: charge floor(quantity * priceCents * (100 - p) / 100) cents for the full product record.
sku|bxyf|x|y: each complete group of x + y units contains y free units. The charged count is quantity - floor(quantity / (x + y)) * y.

A SKU has at most one promotion of each type. For every valid product record, choose the minimum of its regular price and every applicable promoted price. A product without a promotion uses its regular price.

Function

minimumProductTotal(products: String[], promotions: String[]) → long

Examples

Example 1

products = ["A|Apple|3|100","B|Bread|2|250","C|Bad|-1|900"]promotions = ["A|pct|20","A|bxyf|2|1","B|pct|10"]return = 650

For A, buy-two-get-one-free charges 200, cheaper than the 240 percentage price. B costs 450 after 10% off. The negative-quantity C record is skipped.

Example 2

products = ["X|Item|5|99","X|Again|2|99","Y|Free|0|500","Z|Skip|1|-5"]promotions = ["X|bxyf|2|1","Y|pct|100"]return = 594

The two X records are priced independently at 396 and 198. Zero quantity contributes zero, and the negative-price record is skipped.

Example 3

products = ["A|A|1|101","B|B|7|80","C|C|2|200"]promotions = ["A|pct|33","B|bxyf|2|1"]return = 867

The percentage price for A floors 67.67 to 67 cents. B charges five of seven units for 400, and unpromoted C costs 400.

Constraints

0 <= products.length <= 10^5 and 0 <= promotions.length <= 2 * 10^5.
Every record is syntactically valid, and string fields do not contain |.
For percentage promotions, 0 <= p <= 100.
For buy-x-get-y-free promotions, x and y are positive.
Every intermediate line price and the final answer fit in a signed 64-bit integer.