Given a 2D binary matrix filled with 0's and 1's, find the largest square containing only 1's and return its area.
Example:
Input: 1 0 1 0 0 1 0 1 1 1 1 1 1 1 1 1 0 0 1 0 Output: 4
class Solution(object): def maximalSquare(self, matrix): """ :type matrix: List[List[str]] :rtype: int """ if matrix == []: return 0 m = len(matrix) n = len(matrix[0]) maxedge = 0 for i in range(m): for j in range(n): matrix[i][j] = int(matrix[i][j]) if matrix[i][j] and i and j: matrix[i][j] = min(matrix[i][j-1], matrix[i-1][j], matrix[i-1][j-1]) + 1 maxedge = max(maxedge, matrix[i][j]) return maxedge **2