예제 #1
0
        public void MergingTwoHeapsAndCheckingIfExtractedInSortedOrder()
        {
            var heap1 = new BinaryMinHeap <int>();
            var heap2 = new BinaryMinHeap <int>();

            int maxElementInFirstHeap    = 100000;
            int minElementInFirstHeap    = 0;
            int addedElementsInFirstHeap = 0;

            //Adding every seventh number, then every fifth number,
            //every third and at last all numbers
            //NOTE: some items are added more than once
            for (int i = 7; i > 0; i -= 2)
            {
                int el = minElementInFirstHeap;
                while (el <= maxElementInFirstHeap)
                {
                    heap1.Add(el);
                    addedElementsInFirstHeap++;
                    el += i;
                }
            }

            int maxElementInSecondHeap    = 50000;
            int minElementInSecondHeap    = -50000;
            int addedElementsInSecondHeap = 0;

            //Adding every seventh number, then every fifth number,
            //every third and at last all numbers
            //NOTE: some items are added more than once
            for (int i = 7; i > 0; i -= 2)
            {
                int el = minElementInSecondHeap;
                while (el <= maxElementInSecondHeap)
                {
                    heap2.Add(el);
                    addedElementsInSecondHeap++;
                    el += i;
                }
            }

            if (heap1.Count != addedElementsInFirstHeap)
            {
                Assert.Fail("first heap incorrect count");
            }
            if (heap2.Count != addedElementsInSecondHeap)
            {
                Assert.Fail("second heap incorrect count");
            }

            var oldHeap = new BinaryMinHeap <int>();

            oldHeap.Heapify(heap1.ToArray());

            heap1.Merge(heap2);
            heap2.Merge(oldHeap);

            int mergedHeapElements = addedElementsInFirstHeap + addedElementsInSecondHeap;

            if (heap1.Count != mergedHeapElements)
            {
                Assert.Fail("merged first with second incorect count");
            }
            if (heap2.Count != mergedHeapElements)
            {
                Assert.Fail("merged second with first incorrect count");
            }

            var min1 = heap1.PeekMin();
            var min2 = heap2.PeekMin();

            if (min1 != min2)
            {
                Assert.Fail("merged heaps min element is different");
            }

            int removedElements = 0;

            while (!heap1.IsEmpty && !heap2.IsEmpty)
            {
                if (min1 > heap1.PeekMin())
                {
                    Assert.Fail();
                }
                if (min2 > heap2.PeekMin())
                {
                    Assert.Fail();
                }

                min1 = heap1.PopMin();
                min2 = heap2.PopMin();
                removedElements++;

                if (min1 != min2)
                {
                    Assert.Fail("merged heaps min element is different");
                }
            }

            Assert.IsTrue(heap1.IsEmpty &&
                          heap2.IsEmpty &&
                          heap1.Count == 0 &&
                          heap2.Count == 0 &&
                          mergedHeapElements == removedElements);
        }