private static void MinHeapTesting()
        {
            MinBinaryHeap <int> minHeap = new MinBinaryHeap <int>(6);

            int[] arr = new int[] { 12, 11, 13, 5, 6, 7, 50, 49, 1 };

            for (int i = 0; i < 6; i++)
            {
                minHeap.Insert(arr[i]);
            }

            for (int i = 6; i < arr.Length; i++)
            {
                if (minHeap.Peek() > arr[i])
                {
                    minHeap.DeleteMin();
                    minHeap.Insert(arr[i]);
                }
            }

            //minHeap.Insert(12);
            //minHeap.Insert(11);
            //minHeap.Insert(13);
            //minHeap.Insert(5);
            //minHeap.Insert(6);
            //minHeap.Insert(7);
            //minHeap.Insert(50);
            //minHeap.Insert(49);
            //minHeap.Insert(1);
        }
        private static void TopKFrequent()
        {
            string[] words = new string[] { "the", "day", "day", "day", "day", "day", "is", "sunny", "the", "the", "the", "sunny", "is", "is", };
            int      k     = 2;
            Dictionary <string, int> dict = new Dictionary <string, int>();

            for (int i = 0; i < words.Length; i++)
            {
                if (!dict.ContainsKey(words[i]))
                {
                    dict.Add(words[i], 1);
                }
                else
                {
                    dict[words[i]]++;
                }
            }

            MinBinaryHeap <string> minHeap = new MinBinaryHeap <string>(k);
            int j = 0;

            foreach (var item in dict)
            {
                if (minHeap.N == k)
                {
                    var peek = minHeap.Peek();
                    if (item.Value > dict[peek])
                    {
                        minHeap.DeleteMin();
                        minHeap.Insert(item.Key);
                    }

                    continue;
                }

                minHeap.Insert(item.Key);
            }

            List <string> strList = new List <string>();
            int           l       = minHeap.N;

            while (l-- > 0)
            {
                strList.Add(minHeap.DeleteMin());
            }

            for (int i = 0; i < strList.Count; i++)
            {
                Console.Write(strList[i] + " ");
            }
        }