From 28075ba3b5b1af03b6056735ae32bd54d435a1bb Mon Sep 17 00:00:00 2001
From: Aleksei Litkovetc <aleksei_litkovetc@epam.com>
Date: Mon, 1 May 2017 22:33:38 +0300
Subject: [PATCH] Part 1 RectangleSpliterator
---
.../part1/exercise/RectangleSpliterator.java | 34 +++++++++++----
.../part1/example/ArrayExampleTest.java | 18 ++++++++
.../exercise/RectangleSpliteratorTest.java | 42 +++++++++++++++++++
3 files changed, 86 insertions(+), 8 deletions(-)
create mode 100644 src/test/java/spliterators/part1/example/ArrayExampleTest.java
create mode 100644 src/test/java/spliterators/part1/exercise/RectangleSpliteratorTest.java
diff --git a/src/main/java/spliterators/part1/exercise/RectangleSpliterator.java b/src/main/java/spliterators/part1/exercise/RectangleSpliterator.java
index 678f4f5..96653bf 100755
--- a/src/main/java/spliterators/part1/exercise/RectangleSpliterator.java
+++ b/src/main/java/spliterators/part1/exercise/RectangleSpliterator.java
@@ -1,6 +1,5 @@
package spliterators.part1.exercise;
-
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.IntConsumer;
@@ -9,11 +8,11 @@ public class RectangleSpliterator extends Spliterators.AbstractIntSpliterator {
private final int innerLength;
private final int[][] array;
- private final int startOuterInclusive;
+ private int startOuterInclusive;
private final int endOuterExclusive;
- private final int startInnerInclusive;
+ private int startInnerInclusive;
- public RectangleSpliterator(int[][] array) {
+ RectangleSpliterator(int[][] array) {
this(array, 0, array.length, 0);
}
@@ -29,8 +28,18 @@ private RectangleSpliterator(int[][] array, int startOuterInclusive, int endOute
@Override
public OfInt trySplit() {
- // TODO
- throw new UnsupportedOperationException();
+ int length = endOuterExclusive - startOuterInclusive;
+ if (length <= 1) {
+ return null;
+ }
+
+ int middle = startOuterInclusive + length/2;
+
+ final RectangleSpliterator newSpliterator = new RectangleSpliterator(array, startOuterInclusive, middle, startInnerInclusive);
+
+ startOuterInclusive = middle;
+
+ return newSpliterator;
}
@Override
@@ -40,7 +49,16 @@ public long estimateSize() {
@Override
public boolean tryAdvance(IntConsumer action) {
- // TODO
- throw new UnsupportedOperationException();
+ if (startInnerInclusive >= innerLength) {
+ if (startOuterInclusive < endOuterExclusive - 1) {
+ startOuterInclusive += 1;
+ startInnerInclusive = 0;
+ } else {
+ return false;
+ }
+ }
+ action.accept(array[startOuterInclusive][startInnerInclusive]);
+ startInnerInclusive += 1;
+ return true;
}
}
diff --git a/src/test/java/spliterators/part1/example/ArrayExampleTest.java b/src/test/java/spliterators/part1/example/ArrayExampleTest.java
new file mode 100644
index 0000000..035e88f
--- /dev/null
+++ b/src/test/java/spliterators/part1/example/ArrayExampleTest.java
@@ -0,0 +1,18 @@
+package spliterators.part1.example;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.stream.StreamSupport;
+
+public class ArrayExampleTest {
+ @Test
+ public void IntArraySpliterator() {
+ int[] array = new int[] {1, 2, 3, 4, 5};
+ final boolean parallel = false;
+ long res = StreamSupport.intStream(new ArrayExample.IntArraySpliterator(array), parallel)
+ .asLongStream()
+ .sum();
+ Assert.assertEquals(15L, res);
+ }
+}
diff --git a/src/test/java/spliterators/part1/exercise/RectangleSpliteratorTest.java b/src/test/java/spliterators/part1/exercise/RectangleSpliteratorTest.java
new file mode 100644
index 0000000..48c1d66
--- /dev/null
+++ b/src/test/java/spliterators/part1/exercise/RectangleSpliteratorTest.java
@@ -0,0 +1,42 @@
+package spliterators.part1.exercise;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.stream.StreamSupport;
+
+import static org.junit.Assert.assertEquals;
+
+public class RectangleSpliteratorTest {
+ private int[][] array;
+
+ @Before
+ public void setup() {
+ int outerLength = 2;
+ array = new int[outerLength][];
+ for (int i = 0; i < array.length; i++) {
+ int innerLength = 2;
+ int[] inner = new int[innerLength];
+ array[i] = inner;
+ for (int j = 0; j < inner.length; j++) {
+ inner[j] = ThreadLocalRandom.current().nextInt();
+ }
+ }
+ }
+
+ @Test
+ public void testIt(){
+ long sum1 = Arrays.stream(array)
+ .parallel()
+ .flatMapToInt(Arrays::stream)
+ .asLongStream()
+ .sum();
+
+ long sum = StreamSupport.intStream(new RectangleSpliterator(array), true)
+ .asLongStream()
+ .sum();
+ assertEquals(sum1, sum);
+ }
+}
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