输入若干组长度各异的待排序列，分别用快速排序算法和改进的枢轴元素三者取中算法对待排序列进行排序，当待排子序列长度已小于 20时，改用直接插入排序，利用时间函数验证三者取中算法在效率上的提高。（提示： 待排序列的长度一般应为 5000 以上）-Enter the number of head of varying degrees to be sorted out, respectively, using quick sort algorithm and improve the three elements of the pivot algorithm for treatment access in order to sort out, when the question has been ranked sub-sequence length is less than 20:00 in favor of a direct insertion sort , using a function of time to verify the three check in algorithm improve efficiency. (Hint: when to sort out the length of the general should be more than 5000)