Let A be an N-by-N matrix of zeros and ones. A submatrix S of A is any

Question:

Let A be an N-by-N matrix of zeros and ones. A submatrix S of A is any group of contiguous entries that forms a square.
a. Design an O(N2) algorithm that determines the size of the largest submatrix of ones in A. For instance, in the matrix that follows, the largest submatrix is a 4-by-4 square.
10111000
00010100
00111000
00111010
00111111
01011110
01011110
00011110
b. Repeat part (a) if S is allowed to be a rectangle instead of a square. Largest is measured by area.