221.Maximal-Square.cpp

class Solution {
public:
    int maximalSquare(vector<vector<char>>& matrix) {
        int rows = matrix.size();
        int cols = matrix[0].size();
        vector <vector <int>> dp(rows + 1, vector <int>(cols + 1));
        int ans = 0;
        for (int i = 1; i <= rows; i++) {
            for (int j = 1; j <= cols; j++) {
                if (matrix[i - 1][j - 1] == '1'){
                    dp[i][j] = min({dp[i][j - 1], dp[i - 1][j], dp[i - 1][j - 1]}) + 1;
                    ans = max(ans, dp[i][j]);
                }
            }
        }
        return ans * ans;
    }
};