1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41

class Solution {
public:
    int maximalRectangle(vector<vector<char>> &matrix) {
        int max = 0;
        int **map = new int*[matrix.size()];
        for(int i = 0; i < matrix.size(); i++) {
            map[i] = new int[matrix[0].size()];
        }
        for(int i = 0; i < matrix.size(); i++) {
            int height = 0;
            for(int j = matrix[0].size() - 1; j >= 0; j--) {
                if(matrix[i][j] == '1') map[i][j] = ++height;
                else {
                    height = 0;
                    map[i][j] = height;
                }
            }
        }
        for(int i = 0; i < matrix.size(); i++) {
            for(int j = 0; j < matrix[0].size(); j++) {
                int width = map[i][j];
                max = Max(max, width);
                for(int k = i + 1; k < matrix.size(); k++) {
                    if(map[k][j] == 0) break;
                    else {
                        width = Min(width, map[k][j]);
                        max = Max(max, width * (k - i + 1));
                    }
                }
            }
        }
        return max;
    }
private:
    int Max(int a, int b) {
        return a > b ? a : b;
    }
    int Min(int a, int b) {
        return a < b ? a : b;
    }
};