updated CountSquareSubmatricesWithAllOnes with DP solution

Author: minhyeong-joe

Medium/CountSquareWithOnes/Driver.java

@@ -0,0 +1,11 @@
+package Medium.CountSquareWithOnes;
+
+public class Driver {
+ 
+ public static void main(String[] args) {
+ Solution sol = new Solution();
+ int[][] matrix = {{0,1,1,1}, {1,1,1,1}, {0,1,1,1}};
+ System.out.println("output: " + sol.countSquares(matrix));
+ }
+
+}

Medium/CountSquareWithOnes/Solution.java

@@ -0,0 +1,40 @@
+package Medium.CountSquareWithOnes;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Solution
+ */
+public class Solution {
+
+ public int countSquares(int[][] matrix) {
+ int count = 0;
+ // covert primitive int array into ArrayList for easier manipulation
+ List<List<Integer>> mat = new ArrayList<>();
+ for (int[] row: matrix) {
+ List<Integer> list = new ArrayList<>();
+ for (int num: row) {
+ list.add(num);
+ }
+ mat.add(list);
+ }
+ // System.out.println("=== DEBUG: PRINT ARRAYLIST ===");
+ // System.out.println(mat.toString());
+ // go through each col by row
+ for (int i = 0; i < mat.size(); i++) {
+ for (int j = 0; j < mat.get(0).size(); j++) {
+ // System.out.printf("=== %d, %d: %d ===\n", i, j, mat.get(i).get(j));
+ if (i > 0 && j > 0 && mat.get(i).get(j) > 0) {
+ // accumulate
+ int min = Math.min(Math.min(mat.get(i-1).get(j), mat.get(i).get(j-1)), mat.get(i-1).get(j-1));
+ // System.out.println("MIN: " + min);
+ mat.get(i).set(j, mat.get(i).get(j)+min);
+ }
+ count += mat.get(i).get(j);
+ // System.out.println("Count: " + count);
+ }
+ }
+ return count;
+ }
+}