How should I practice Exact-Sixty Dice Game Value?

Start by reading the full statement, solve the visible examples, then compare the pattern against related Jane Street onsite interview problems in FastPrep.

Is Exact-Sixty Dice Game Value associated with Jane Street?

FastPrep tags this as a Jane Street onsite interview coding practice problem when the problem catalog has that company and stage context.

Exact-Sixty Dice Game Value

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Problem statement

Choose one available fair die and roll it once. A die with s sides has equally likely integer faces from 1 through s. The roll costs 1, and rolling exactly 60 pays 100.

Return the side count with the greatest exact expected net value as side|numerator/denominator, where the reduced fraction is also the fair midpoint for the round. Ties choose the smaller side count. Dice with fewer than 60 sides can never win the payout and therefore have net value -1/1.

Function

bestExactSixtyDie(sideCounts: int[]) → String

Examples

Example 1

sideCounts = [10,20,30,40,50,60,70,80,90,100]return = "60|2/3"

The 60-sided die has net expectation 100/60 - 1 = 2/3, larger than every other available die.

Example 2

sideCounts = [6,20,50]return = "6|-1/1"

No die can roll 60, so every option has net value -1 and the smallest side count wins the tie.

Constraints

1 <= sideCounts.length <= 10^5.
1 <= sideCounts[i] <= 10^9.
Side counts may repeat.