Code RoomExpected die rolls to target
MediumPrep Room Coding #835

Expected die rolls to target

CodingAlgorithms & data structuresMid–Senior~30 min

You repeatedly roll a fair k-sided die (faces 1..k) and accumulate the sum. You stop the moment the running total is >= target. Return the expected number of rolls, rounded to 6 decimal places. 1 <= k <= 20, 0 <= target <= 1000.

Implement
expected_rolls(k: int, target: int) → float
Examples
in[6,1]out1
What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

0:00 of about 30 min
InputExpectedGot
[6,1]1not run yetsample