Code RoomFind duplicate number
HardPrep Room Coding #1602

Find duplicate number

CodingAlgorithms & data structuresSenior–Staff~35 min

An array of n+1 integers has each value in 1..n with exactly one value repeated. Return the duplicate without modifying the array and in O(1) space.

Implement
find_duplicate(nums: list[int]) → int
Examples
in[[1,3,4,2,2]]out2
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 35 min
InputExpectedGot
[[1,3,4,2,2]]2not run yetsample