public class Solution {
    public int maximalRectangle(char[][] matrix) {

        int max = 0;
        for (int i = 0; i < matrix.length; i++) {
            for (int j = 0; j < matrix[0].length; j++) {
                int width = 0;
                int height = 0;

                for (int k = i; k < matrix.length && matrix[k][j] == '1'; k++) {
                    width++;
                }

                for (int k = i; k < i + width; k++) {
                    for (int l = j; l < matrix[0].length; l++) {
                        if (matrix[k][l] == '0') {
                            width = k - i;
                            if (width * height > max) {
                                max = width * height;
                            }
                        }
                    }
                    height++;
                }

                if (width * height > max) {
                    max = width * height;
                }

            }
        }
        return max;
    }

    public static void main(String[] args) {

        Solution solution = new Solution();
        System.out.println(solution.maximalRectangle(new char[][]{{'1', '0', '1', '0', '0'}, {'1', '0', '1', '1', '1'}, {'1', '1', '1', '1', '1'}, {'1', '0', '0', '1', '0'}}));
        System.out.println(solution.maximalRectangle(new char[][]{{'1'}, {'0'}}));
    }
}