Count all-ones square submatrices
Given an m x n binary matrix (entries are 0 or 1), count how many square submatrices have all entries equal to 1. Squares of every side length count, and squares overlapping each other are counted separately. Return the total number of all-ones square submatrices. Dimensions are at least 1x1 and at most 300x300.
Implement
count_squares(matrix: list[list[int]]) → intExamples
in
[[[0,1,1,1],[1,1,1,1],[0,1,1,1]]]out15What 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 20 min
solution.py
InputExpectedGot
[[[0,1,1,1],[1,1,1,1],[0,1,1,1]]]15not run yetsample