Create package prime, matrix and games (#6139)

src/test/java/com/thealgorithms/matrix/MatrixUtilTest.java

@@ -0,0 +1,80 @@
+package com.thealgorithms.matrix;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import com.thealgorithms.matrix.utils.MatrixUtil;
+import java.math.BigDecimal;
+import java.util.Objects;
+import org.junit.jupiter.api.Test;
+
+class MatrixUtilTest {
+
+    @Test
+    void add() {
+        final BigDecimal[][] matrix1 = {
+            {new BigDecimal(3), BigDecimal.TWO},
+            {BigDecimal.ZERO, BigDecimal.ONE},
+        };
+
+        final BigDecimal[][] matrix2 = {
+            {BigDecimal.ONE, new BigDecimal(3)},
+            {BigDecimal.TWO, BigDecimal.ZERO},
+        };
+
+        final BigDecimal[][] actual = MatrixUtil.add(matrix1, matrix2).orElseThrow(() -> new AssertionError("Could not compute matrix!"));
+
+        final BigDecimal[][] expected = {
+            {new BigDecimal(4), new BigDecimal(5)},
+            {BigDecimal.TWO, BigDecimal.ONE},
+        };
+
+        assertTrue(Objects.deepEquals(actual, expected));
+    }
+    @Test
+    void subtract() {
+        final BigDecimal[][] matrix1 = {
+            {BigDecimal.ONE, new BigDecimal(4)},
+            {new BigDecimal(5), new BigDecimal(6)},
+        };
+
+        final BigDecimal[][] matrix2 = {
+            {BigDecimal.TWO, BigDecimal.ZERO},
+            {new BigDecimal(-2), new BigDecimal(-3)},
+        };
+
+        final BigDecimal[][] actual = MatrixUtil.subtract(matrix1, matrix2).orElseThrow(() -> new AssertionError("Could not compute matrix!"));
+
+        final BigDecimal[][] expected = {
+            {new BigDecimal(-1), new BigDecimal(4)},
+            {new BigDecimal(7), new BigDecimal(9)},
+        };
+
+        assertTrue(Objects.deepEquals(actual, expected));
+    }
+
+    @Test
+    void multiply() {
+
+        final BigDecimal[][] matrix1 = {
+            {BigDecimal.ONE, BigDecimal.TWO, new BigDecimal(3)},
+            {new BigDecimal(4), new BigDecimal(5), new BigDecimal(6)},
+            {new BigDecimal(7), new BigDecimal(8), new BigDecimal(9)},
+        };
+
+        final BigDecimal[][] matrix2 = {
+            {BigDecimal.ONE, BigDecimal.TWO},
+            {new BigDecimal(3), new BigDecimal(4)},
+            {new BigDecimal(5), new BigDecimal(6)},
+        };
+
+        final BigDecimal[][] actual = MatrixUtil.multiply(matrix1, matrix2).orElseThrow(() -> new AssertionError("Could not compute matrix!"));
+
+        final BigDecimal[][] expected = {
+            {new BigDecimal(22), new BigDecimal(28)},
+            {new BigDecimal(49), new BigDecimal(64)},
+            {new BigDecimal(76), new BigDecimal(100)},
+        };
+
+        assertTrue(Objects.deepEquals(actual, expected));
+    }
+}