6 When searching a table with length n by binary search, how many comparisons are needed in the worst case? (1.84) A nlogn Blogn+1 logn Dn 21 If the data sequence (11,12,13,7,8,9,23,4,5) is the result of the second sorting result of a sort algorithm then the sort algorithm can only be (1.89) A select sort B insert sort merge sort D bubble sort 18 If the time complexity of an algorithm is (1), it means (1.84) A With the increase of the scale of the problem, the growth rate of the running time of the algorithm is 1 B. The running time of the algorithm is 1s C The number of basic operations in the algorithm is independent of the data size of the problem The algorithm contains only one basic operation