dp bottom up lc 221 maximal square java

Author: user54778

java/0221-maximal-square.java

@@ -0,0 +1,17 @@
+class Solution {
+    // dp bottom up
+    public int maximalSquare(char[][] matrix) {
+        int[][] dp = new int[matrix.length + 1][matrix[0].length + 1];
+        int maxLen = 0;
+        for (int row = matrix.length - 1; row >= 0; row--) {
+            for (int col = matrix[0].length - 1; col >= 0; col--) {
+                if (matrix[row][col] == '1') {
+                    dp[row][col] = 1 + Math.min(Math.min(dp[row + 1][col], dp[row][col + 1]), dp[row + 1][col + 1]);
+                    maxLen = Math.max(maxLen, dp[row][col]);
+                }
+            }
+        }
+
+        return maxLen * maxLen;
+    }
+}