A cinema hall is shown as a grid of characters. A cell with "1" is a free seat. A cell with "0" is a seat that is taken or broken.
A group wants to sit together in a solid rectangle of seats where every seat is free. Find the biggest such rectangle and return its area (the number of seats in it).
If there is no free seat at all, return 0.
Examples
Example 1:
Input: matrix = [["1","1","0"],["1","1","1"]]
Output: 4
Explanation: The left two columns form a 2 x 2 block of free seats, so the area is 4.
Example 2:
Input: matrix = [["1","0","1","1"],["1","1","1","1"],["1","1","1","0"]]
Output: 6
Explanation: Rows 2 and 3 both have three free seats side by side, so the biggest block is 2 x 3 = 6.
Example 3:
Input: matrix = [["0","0","0"]]
Output: 0
Explanation: No seat is free, so the area is 0.