CodingHardcod-g077

Subject Kth elementLevel Senior–Staff~35 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given an n x n matrix where each row is sorted in ascending order (rows are independently sorted; columns are NOT necessarily sorted), and an integer k (1-indexed, 1 <= k <= total elements), return the k-th smallest element across the whole matrix. Duplicate values count as separate elements.

Implement

kth_smallest_in_matrix(matrix: list[list[int]], k: int) → int

Examples

in[[[1,5,9],[10,11,13],[12,13,15]],8]out13

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.

Learn the concepts

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.