Resolves Java 2D Array Task

src/main/java/eu/ztsh/training/hackerrank/datastructures/array_2d/Solution.java

@@ -0,0 +1,55 @@
+package eu.ztsh.training.hackerrank.datastructures.array_2d;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+/**
+ * Java 2D Array task.
+ * source: https://www.hackerrank.com/challenges/java-2d-array/problem
+ */
+public class Solution {
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+
+        List<List<Integer>> arr = new ArrayList<>();
+
+        IntStream.range(0, 6).forEach(i -> {
+            try {
+                arr.add(
+                        Stream.of(bufferedReader.readLine().replaceAll("\\s+$", "").split(" "))
+                                .map(Integer::parseInt)
+                                .collect(Collectors.toList())
+                );
+            } catch (IOException ex) {
+                throw new RuntimeException(ex);
+            }
+        });
+
+        var array = arr.stream().map(l -> l.stream().mapToInt(i -> i).toArray()).toArray(int[][]::new);
+        var max = new AtomicInteger(Integer.MIN_VALUE);
+        IntStream.range(1, 5).forEach(row -> IntStream.range(1, 5).forEach(col -> {
+            var result = countHourglass(array, row, col);
+            if (result > max.get()) {
+                max.set(result);
+            }
+        }));
+
+        System.out.println(max.get());
+        bufferedReader.close();
+    }
+
+    private static int countHourglass(int[][] array, int row, int col) {
+        return array[row - 1][col - 1] + array[row - 1][col] + array[row - 1][col + 1] +
+                array[row][col] +
+                array[row + 1][col - 1] + array[row + 1][col] + array[row + 1][col + 1];
+    }
+
+}

src/test/java/eu/ztsh/training/hackerrank/EnvironmentTest.java

@@ -1,5 +1,8 @@
 package eu.ztsh.training.hackerrank;
 
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
 import java.util.List;
 import java.util.Scanner;
 import eu.ztsh.training.hackerrank.SolutionClassDescription.FieldModifier;
@@ -86,6 +89,17 @@ public class EnvironmentTest {
 
     }
 
+    @Nested
+    @DisplayName("Test with BufferedReader created in main(String[]) method")
+    class EnvironmentReaderTest extends HackerRankEnvironmentTest {
+
+        @Override
+        protected SolutionClassDescription getSolutionClassDescription() {
+            return new SolutionClassDescription(SampleSolutionWithInlineBufferedReader.class);
+        }
+
+    }
+
 }
 
 class SampleSolutionWithPrivateStaticScanner {
@@ -123,3 +137,16 @@ class SampleSolutionWithInlineScanner {
     }
 
 }
+
+class SampleSolutionWithInlineBufferedReader {
+
+    public static void main(String... args) throws IOException {
+        var bufferedReader = new BufferedReader(new InputStreamReader(System.in));
+        String line = bufferedReader.readLine();
+        do {
+            System.out.println(line);
+            line = bufferedReader.readLine();
+        } while (line != null);
+    }
+
+}

src/test/java/eu/ztsh/training/hackerrank/datastructures/array_2d/SolutionTest.java

@@ -0,0 +1,70 @@
+package eu.ztsh.training.hackerrank.datastructures.array_2d;
+
+import java.util.List;
+import eu.ztsh.training.hackerrank.HackerRankTest;
+import eu.ztsh.training.hackerrank.SolutionClassDescription;
+import org.junit.jupiter.api.DisplayName;
+import org.junit.jupiter.api.Test;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DisplayName("HackerRank challenges: Java 2D Array")
+class SolutionTest extends HackerRankTest {
+
+    @Test
+    public void dummyInitTest() {
+        assertThat(true).isTrue();
+    }
+
+    @Test
+    public void testCase0() {
+        simpleAssert(
+                List.of(
+                        "1 1 1 0 0 0",
+                        "0 1 0 0 0 0",
+                        "1 1 1 0 0 0",
+                        "0 0 2 4 4 0",
+                        "0 0 0 2 0 0",
+                        "0 0 1 2 4 0"
+                ),
+                List.of("19")
+        );
+    }
+
+    @Test
+    public void testCase1() {
+        simpleAssert(
+                List.of(
+                        "1 1 1 0 0 0",
+                        "0 1 0 0 0 0",
+                        "1 1 1 0 0 0",
+                        "0 9 2 -4 -4 0",
+                        "0 0 0 -2 0 0",
+                        "0 0 -1 -2 -4 0"
+                ),
+                List.of("13")
+        );
+    }
+
+    @Test
+    public void testCase3() {
+        simpleAssert(
+                List.of(
+                        "-1 -1 0 -9 -2 -2",
+                        "-2 -1 -6 -8 -2 -5",
+                        "-1 -1 -1 -2 -3 -4",
+                        "-1 -9 -2 -4 -4 -5",
+                        "-7 -3 -3 -2 -9 -9",
+                        "-1 -3 -1 -2 -4 -5"
+                ),
+                List.of("-6")
+        );
+    }
+
+
+    @Override
+    protected SolutionClassDescription getSolutionClassDescription() {
+        return new SolutionClassDescription(Solution.class);
+    }
+
+}