Code RoomPivot index
EasyPrep Room Coding #477

Pivot index

CodingAlgorithms & data structuresEntry–Mid~12 min

Given a list of integers, find the smallest index i such that the sum of the elements strictly to the left of i equals the sum of the elements strictly to the right of i. The element at i itself belongs to neither side, and an empty side sums to 0. Return that index, or -1 if no such index exists. Values may be negative. Example: nums = [1, 7, 3, 6, 5, 6] gives 3, since 1 + 7 + 3 = 5 + 6 = 11.

Implement
pivot_index(nums: list[int]) → int
Examples
in[[1,7,3,6,5,6]]out3
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 12 min
InputExpectedGot
[[1,7,3,6,5,6]]3not run yetsample