221. Maximal Square

https://leetcode.com/problems/maximal-square/description/

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

    int row = matrix.length;
    if(row == 0) return 0;
    int col = matrix[0].length;
    int[][] dp = new int[row][col];
    int sum = 0;
    for(int i = 0; i < row; i++){
        if(matrix[i][0] == '1'){
            dp[i][0] = 1;
            sum = Math.max(sum, dp[i][0]);
        }else{
            dp[i][0] = 0;
        }
    }
    for(int i = 0; i < col; i++){
        if(matrix[0][i] == '1'){
            dp[0][i] = 1;
            sum = Math.max(sum, dp[0][i]);
        }else{
            dp[0][i] = 0;
        }
    }
    for(int i = 1; i < row; i++){
        for(int j = 1; j < col; j++){
            if(matrix[i][j] == '0')
                dp[i][j] = 0;
            else{
                dp[i][j] = Math.min(Math.min(dp[i-1][j-1],dp[i-1][j]), dp[i][j-1])+1;
                sum = Math.max(sum, dp[i][j]);
            }
        }
    }
    return (int)Math.pow(sum, 2);
}

}