Code RoomSubmatrix sum count
MediumPrep Room Coding #986

Submatrix sum count

CodingAlgorithms & data structuresMid–Senior~25 min

Given an m x n integer matrix and an integer target, count the number of (non-empty) axis-aligned submatrices whose elements sum exactly to target. A submatrix is defined by a contiguous range of rows and a contiguous range of columns. Matrix dimensions are up to 100 x 100 and entries may be negative.

Implement
count_target_submatrices(matrix: list[list[int]], target: int) → int
Examples
in[[[0,1,0],[1,1,1],[0,1,0]],0]out4
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 25 min
InputExpectedGot
[[[0,1,0],[1,1,1],[0,1,0]],0]4not run yetsample