diff --git a/src/main/java/spliterators/part2/example/ArrayZipWithIndexExample.java b/src/main/java/spliterators/part2/example/ArrayZipWithIndexExample.java
index dd00263..96da908 100755
--- a/src/main/java/spliterators/part2/example/ArrayZipWithIndexExample.java
+++ b/src/main/java/spliterators/part2/example/ArrayZipWithIndexExample.java
@@ -8,7 +8,6 @@ public class ArrayZipWithIndexExample {
 
     public static class IndexedArraySpliterator<T> extends Spliterators.AbstractSpliterator<IndexedPair<T>> {
 
-
         private final T[] array;
         private int startInclusive;
         private final int endExclusive;
diff --git a/src/main/java/spliterators/part2/exercise/IndexedDoublePair.java b/src/main/java/spliterators/part2/exercise/IndexedDoublePair.java
index d3c0162..424948b 100755
--- a/src/main/java/spliterators/part2/exercise/IndexedDoublePair.java
+++ b/src/main/java/spliterators/part2/exercise/IndexedDoublePair.java
@@ -5,15 +5,15 @@
 import org.apache.commons.lang3.builder.ToStringBuilder;
 
 public class IndexedDoublePair {
-    private final int index;
+    private final long index;
     private final double value;
 
-    public IndexedDoublePair(int index, double value) {
+    public IndexedDoublePair(long index, double value) {
         this.index = index;
         this.value = value;
     }
 
-    public int getIndex() {
+    public long getIndex() {
         return index;
     }
 
diff --git a/src/main/java/spliterators/part2/exercise/ZipWithIndexDoubleSpliterator.java b/src/main/java/spliterators/part2/exercise/ZipWithIndexDoubleSpliterator.java
index deb4867..8bc9ddf 100755
--- a/src/main/java/spliterators/part2/exercise/ZipWithIndexDoubleSpliterator.java
+++ b/src/main/java/spliterators/part2/exercise/ZipWithIndexDoubleSpliterator.java
@@ -1,20 +1,20 @@
 package spliterators.part2.exercise;
 
+import java.util.Comparator;
 import java.util.Spliterator;
 import java.util.Spliterators;
 import java.util.function.Consumer;
 
 public class ZipWithIndexDoubleSpliterator extends Spliterators.AbstractSpliterator<IndexedDoublePair> {
 
-
     private final OfDouble inner;
-    private int currentIndex;
+    private long currentIndex;
 
     public ZipWithIndexDoubleSpliterator(OfDouble inner) {
         this(0, inner);
     }
 
-    private ZipWithIndexDoubleSpliterator(int firstIndex, OfDouble inner) {
+    private ZipWithIndexDoubleSpliterator(long firstIndex, OfDouble inner) {
         super(inner.estimateSize(), inner.characteristics());
         currentIndex = firstIndex;
         this.inner = inner;
@@ -22,35 +22,40 @@ private ZipWithIndexDoubleSpliterator(int firstIndex, OfDouble inner) {
 
     @Override
     public int characteristics() {
-        // TODO
-        throw new UnsupportedOperationException();
+        return inner.characteristics() | Spliterator.DISTINCT /*& ~Spliterator.SORTED*/;
     }
 
     @Override
     public boolean tryAdvance(Consumer<? super IndexedDoublePair> action) {
-        // TODO
-        throw new UnsupportedOperationException();
+        return inner.tryAdvance((double d) -> action.accept(new IndexedDoublePair(currentIndex++, d)));
+    }
+
+    @Override
+    public Comparator<? super IndexedDoublePair> getComparator() {
+        return (i1, i2) -> inner.getComparator().compare(i1.getValue(),i2.getValue());
     }
 
     @Override
     public void forEachRemaining(Consumer<? super IndexedDoublePair> action) {
-        // TODO
-        throw new UnsupportedOperationException();
+        inner.forEachRemaining(
+                (double d) -> action.accept(new IndexedDoublePair(currentIndex++, d))
+        );
     }
 
     @Override
     public Spliterator<IndexedDoublePair> trySplit() {
-        // TODO
-        // if (inner.hasCharacteristics(???)) {
-        //   use inner.trySplit
-        // } else
+        if (inner.hasCharacteristics(Spliterator.SUBSIZED)) {
+            OfDouble ofDouble = inner.trySplit();
+            currentIndex = currentIndex + estimateSize() / 2;
+            return new ZipWithIndexDoubleSpliterator(0, ofDouble);
+        } else {
+            return super.trySplit();
+        }
 
-        return super.trySplit();
     }
 
     @Override
     public long estimateSize() {
-        // TODO
-        throw new UnsupportedOperationException();
+        return inner.estimateSize();
     }
 }
diff --git a/src/test/java/spliterators/part2/exercise/ZipWithIndexDoubleSpliteratorTest.java b/src/test/java/spliterators/part2/exercise/ZipWithIndexDoubleSpliteratorTest.java
new file mode 100644
index 0000000..33a9b38
--- /dev/null
+++ b/src/test/java/spliterators/part2/exercise/ZipWithIndexDoubleSpliteratorTest.java
@@ -0,0 +1,71 @@
+package spliterators.part2.exercise;
+
+import org.junit.Test;
+
+import java.util.Arrays;
+import java.util.Spliterator;
+import java.util.stream.DoubleStream;
+import java.util.stream.StreamSupport;
+
+import static org.junit.Assert.*;
+
+/**
+ * Created by student on 7/17/17.
+ */
+public class ZipWithIndexDoubleSpliteratorTest {
+
+    private int maxSize;
+
+    @Test
+    public void testPar() {
+        maxSize = 10000;
+        Spliterator.OfDouble spliterator = DoubleStream.iterate(1.0, i -> i + 0.1)
+                .limit(maxSize)
+                .spliterator();
+
+
+        double[] array = generateDouble();
+        double sum = StreamSupport.stream(new ZipWithIndexDoubleSpliterator(Arrays.spliterator(array)), true)
+                .mapToDouble(z -> z.getIndex()*z.getValue())
+                .sum();
+
+        double res = 0.0;
+
+        for (int i = 0; i < maxSize; ++i) {
+            res += i * (array[i]);
+        }
+
+        assertEquals(sum, res, 0.1);
+    }
+
+    private double[] generateDouble() {
+        double[] doubles = new double[maxSize];
+
+        for (double aDouble : doubles) {
+            aDouble = Math.random();
+        }
+
+        return doubles;
+    }
+
+    @Test
+    public void testSeq() {
+        maxSize = 100;
+        Spliterator.OfDouble spliterator = DoubleStream.iterate(1.0, i -> i + 0.1)
+                .limit(maxSize)
+                .spliterator();
+
+        double[] array = generateDouble();
+        double sum = StreamSupport.stream(new ZipWithIndexDoubleSpliterator(Arrays.spliterator(array)), false)
+                .mapToDouble(z -> z.getIndex()*z.getValue())
+                .sum();
+
+        double res = 0.0;
+
+        for (int i = 0; i < maxSize; ++i) {
+            res += i * (array[i]);
+        }
+
+        assertEquals(sum, res, 0.1);
+    }
+}
\ No newline at end of file