示例#1
0
文件: WiggleSort.cs 项目: srp19/ADS
        public virtual void wiggleSort(int[] arr)
        {
            if (arr.Length == 0)
            {
                return;
            }
            int k = arr.Length / 2;
            KthElementInArray kthElementInArray = new KthElementInArray();

            kthElementInArray.kthElement(arr, k);

            int mid = arr[k];
            int n = arr.Length;
            int i = 0, j = 0;

            k = n - 1;
            while (j <= k)
            {
                if (arr[next(j, n)] > mid)
                {
                    swap(arr, next(i++, n), next(j++, n));
                }
                else if (arr[next(j, n)] < mid)
                {
                    swap(arr, next(j, n), next(k--, n));
                }
                else
                {
                    j++;
                }
            }
        }
        public virtual void convert(int[] arr)
        {
            int k = 0;

            if (arr.Length % 2 == 0)
            {
                k = arr.Length / 2;
            }
            else
            {
                k = arr.Length / 2 + 1;
            }
            KthElementInArray kthElement = new KthElementInArray();

            kthElement.kthElement(arr, k);

            int high = k;
            int low  = 1;

            while (low < high && high < arr.Length)
            {
                swap(arr, low, high);
                high++;
                low += 2;
            }
        }
示例#3
0
        public static void Main(String[] args)
        {
            /*
             * Kth largest element in an array.
             * Use quickselect of quicksort to find the solution
             *  in hopefully O(nlogn) time.
             * Test cases
             * Sorted array
             * Reverse sorted array
             */
            int[]             arr        = { 4, 3, 2, 1 };
            KthElementInArray kthElement =
                new KthElementInArray();

            Console.WriteLine(kthElement.kthElement(arr, 2));
        }