选择排序

        /// <summary>
        /// 选择排序
        /// 原理：每次找出最小的元素排在最前面
        /// </summary>
        /// <param name="arr"></param>
        /// <returns></returns>
        public static int[] SelectionSort(int[] ary)
        {
            int m = 0;
            for (int i = 0; i < ary.Length; i++)
            {
                for (int j = 1; j < ary.Length - i; j++)
                {
                    if (ary[m] < ary[j])
                    {
                        m = j;
                    }
                }
                int k = ary.Length - i - 1;
                if (m != k)
                {
                    int t = ary[m];
                    ary[m] = ary[k];
                    ary[k] = t;
                }
                m = 0;
            }
            return ary;
        }