package com.app.main.LeetCode.dynamic;

/**
 *
 * 221
 *
 * medium
 *
 * https://leetcode.com/problems/maximal-square/
 *
 * Given a 2D binary matrix filled with 0's and 1's, find the largest square containing only 1's and return its area.
 *
 * Example:
 *
 * Input:
 *
 * 1 0 1 0 0
 * 1 0 1 1 1
 * 1 1 1 1 1
 * 1 0 0 1 0
 *
 * Output: 4
 *
 * Created with IDEA
 * author:Dingsheng Huang
 * Date:2019/12/20
 * Time:下午4:43
 */
public class MaximalSquare {
    public int maximalSquare(char[][] matrix) {
        int max = 0;
        if (matrix.length == 0) {
            return 0;
        }
        int[][] dp = new int[matrix.length][matrix[0].length];

        for (int i = 0; i < matrix[0].length; i++) {
            if (matrix[0][i] == '1') {
                dp[0][i] = 1;
                max = 1;
            }
        }
        for (int i = 0; i < matrix.length; i++) {
            if (matrix[i][0] == '1') {
                dp[i][0] = 1;
                max = 1;
            }
        }

        for (int i = 1; i < matrix.length; i ++) {
            for (int j = 1; j < matrix[0].length; j++) {
                if (matrix[i][j] == '1') {
                    dp[i][j] = Math.min(Math.min(dp[i - 1][j], dp[i][j - 1]), dp[i - 1][j - 1]) + 1;
                    max = Math.max(max, dp[i][j]);
                }
            }
        }
        return max * max;
    }


}