leetcode221.最大正方形

class Solution {
    public int maximalSquare(char[][] matrix) {
        int result = 0; // 记录正方形边长
        int m = matrix.length, n = matrix[0].length;
        int[][] dp = new int[m + 1][n + 1];
        // 动态规划
        for (int i = 1; i <= m; i++) {
            for (int j = 1; j <= n; j++) {
                if (matrix[i - 1][j - 1] == '0') {
                    dp[i][j] = 0;
                } else {
                    dp[i][j] = 1 + Math.min(Math.min(dp[i - 1][j], dp[i][j - 1]), dp[i - 1][j - 1]);
                    result = Math.max(result, dp[i][j]);
                }
            }
        }
        return result * result;
    }
}