目标
给定一个仅包含 0 和 1 、大小为 rows x cols 的二维二进制矩阵，找出只包含 1 的最大矩形，并返回其面积。
示例 1：
输入：matrix = [["1","0","1","0","0"],["1","0","1","1","1"],["1","1","1","1","1"],["1","0","0","1","0"]]
输出：6
解释：最大矩形如上图所示。示例 2：
输入：matrix = [["0"]]
输出：0示例 3：
输入：matrix = [["1"]]
输出：1说明：
- rows == matrix.length
- cols == matrix[0].length
- 1 <= rows, cols <= 200
- matrix[i][j] 为 '0' 或 '1'
思路
代码