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:
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| Input:
1 0 1 0 0
1 0 1 1 1
1 1 1 1 1
1 0 0 1 0
Output: 4
|
Solution
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| class Solution {
public int maximalSquare(char[][] matrix) {
int n = matrix.length;
if (n == 0) {
return 0;
}
int m = matrix[0].length;
int[][] dp = new int[n][m];
int answer = 0;
for (int i = 0; i < n; ++i) {
for (int j = 0; j < m; ++j) {
if (matrix[i][j] == '1') {
dp[i][j] = 1;
if (i > 0 && j > 0) {
dp[i][j] += Math.min(dp[i - 1][j], Math.min(dp[i][j - 1], dp[i - 1][j - 1]));
}
answer = Math.max(answer, dp[i][j]);
}
}
}
return answer * answer;
}
}
|