class Solution {
public:
int maximalRectangle(const vector<vector<char>> &matrix) const {
const int n = size(matrix), m = size(matrix[0]);
static int dp[202][202] = {0};
int res = 0;
for (int i = n - 1; i >= 0; i--) {
dp[i][m] = 0;
for (int j = m - 1, acc = 0; j >= 0; j--) {
dp[i][j] = matrix[i][j] == '1' ? dp[i][j + 1] + 1 : 0;
}
}
for (int i = 0; i < n; i++) {
for (int j = 0; j < m; j++) {
for (int l = i, len = m; l < n && matrix[l][j] == '1'; l++) {
len = min(len, dp[l][j]);
res = max(res, (l - i + 1) * len);
}
}
}
return res;
}
};