Given a 2D binary matrix, find the area of the largest rectangle containing only 1's.
Sample Input:
[["1","0","1","0","0"],["1","0","1","1","1"],["1","1","1","1","1"],["1","0","0","1","0"]]
Hints
Hint 1
Treat each row as base of histogram
Hint 2
Use largest rectangle in histogram algorithm
Hint 3
Update heights for each row
