题目：
Given a 2D binary matrix filled with 0's and 1's, find the largest square containing all 1's and return its area.
For example, given the following matrix:
1 0 1 0 0 1 0 1 1 1 1 1 1 1 1 1 0 0 1 0
Return 4.
链接： http://leetcode.com/problems/maximal-square/
7/19/2017
看答案做的
1 public class Solution { 2 public int maximalSquare(char[][] matrix) { 3 if (matrix == null || matrix.length == 0 || matrix[0].length == 0) { 4 return 0; 5 } 6 int[] dp = new int[matrix[0].length + 1]; 7 int maxLen = 0; 8 int prev = 0; 9 for (int i = 1; i <= matrix.length; i++) { 10 for (int j = 1; j <= matrix[0].length; j++) { 11 int temp = dp[j]; 12 if (matrix[i - 1][j - 1] == '1') { 13 dp[j] = Math.min(Math.min(dp[j - 1], prev), dp[j]) + 1; 14 maxLen = Math.max(maxLen, dp[j]); 15 } else { 16 dp[j] = 0; 17 } 18 prev = temp; 19 } 20 } 21 return maxLen * maxLen; 22 } 23 }
官方答案
https://leetcode.com/problems/maximal-square/#/solution
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