Add median of matrix (#4590)

src/test/java/com/thealgorithms/misc/MedianOfMatrixtest.java

@@ -0,0 +1,34 @@
+package com.thealgorithms.misc;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+public class MedianOfMatrixtest {
+
+    @Test
+    public void testMedianWithOddNumberOfElements() {
+        List<List<Integer>> matrix = new ArrayList<>();
+        matrix.add(Arrays.asList(1, 3, 5));
+        matrix.add(Arrays.asList(2, 4, 6));
+        matrix.add(Arrays.asList(7, 8, 9));
+
+        int result = MedianOfMatrix.median(matrix);
+
+        assertEquals(5, result);
+    }
+
+    @Test
+    public void testMedianWithEvenNumberOfElements() {
+        List<List<Integer>> matrix = new ArrayList<>();
+        matrix.add(Arrays.asList(2, 4));
+        matrix.add(Arrays.asList(1, 3));
+
+        int result = MedianOfMatrix.median(matrix);
+
+        assertEquals(2, result);
+    }
+}