Java3 lesson 6 homework.

src/lesson6/ArrayMethods.java

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+package lesson6;
+
+public class ArrayMethods {
+
+    public static int[] splitBy4(int [] array){
+        for(int i = array.length - 1; i>0; i--){
+            if(array[i] == 4) {
+                int[] part = new int[array.length - i - 1];
+                System.arraycopy(array, (i + 1), part, 0, part.length);
+                return part;
+            }
+        }
+        throw new RuntimeException("В массиве не обнаружена цифра 4");
+    }
+
+    public static boolean isThereOneOrFour(int[] array){
+
+        boolean isThereOne = false;
+        boolean isThereFour = false;
+
+        if(array.length == 0) return false;
+        else{
+            for(int i = 0; i < array.length; i++){
+                if(array[i] == 1) {
+                    isThereOne = true;
+                }else{
+                    if(array[i] == 4){
+                        isThereFour = true;
+                    } else {
+                        return false;
+                    }
+                }
+            }
+            return isThereFour && isThereOne;
+        }
+    }
+}

src/lesson6/IsThereOneOrFourTest.java

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+package lesson6;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+@RunWith(Parameterized.class)
+public class  IsThereOneOrFourTest{
+    @Parameterized.Parameters
+    public static Collection<Object[]> data() {
+        return Arrays.asList(new Object[][]{
+                {new int[]{1, 1, 4}, true},
+                {new int[]{1, 1, 4, 2, 8}, false},
+                {new int[]{1, 1, 1}, false},
+                {new int[]{4, 4, 4}, false},
+        });
+    }
+
+    private int[] array;
+    private boolean result;
+
+    public IsThereOneOrFourTest(int[] array, boolean result) {
+        this.array = array;
+        this.result = result;
+    }
+
+    @Test
+    public void massTest() {
+        Assert.assertEquals(result, ArrayMethods.isThereOneOrFour(array));
+    }
+}

src/lesson6/SplitBy4Test.java

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+package lesson6;
+
+import org.junit.Assert;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+@RunWith(Parameterized.class)
+public class SplitBy4Test {
+    @Parameterized.Parameters
+    public static Collection<Object[]> data() {
+        return Arrays.asList(new Object[][]{
+                {new int[]{1, 2, 3, 4}, new int[]{}},
+                {new int[]{1, 4, 3, 2, 1}, new int[]{3, 2, 1}},
+                {new int[]{1, 2, 3, 4, 1, 2, 3, 4, 5, 6}, new int[]{5, 6}},
+        });
+    }
+
+    private int[] array;
+    private int[] result;
+
+    public SplitBy4Test(int[] array, int[] result){
+        this.array = array;
+        this.result = result;
+    }
+
+    @Test
+    public void test(){
+        Assert.assertArrayEquals(result, ArrayMethods.splitBy4(array));
+    }
+}