maximalRectangle

Problem

Given a 2D binary matrix filled with 0's and 1's, find the largest rectangle containing all ones and return its area.

Solution

Very difficult problem, need to utilize the method in question "largest rectangle histogram"

1. make a new matrix, where each value is the number of consecutive '1's above it

2. apply "largest rectangle histogram" on each row

3. compare and return max from all rows