In a men's 1000 m physical fitness test, a total of 500 people to attend, time within 3 minutes 20 seconds for good, for more than 4 minutes to unqualified, student id number as the registration information, test results on the final requirement information a) excellent students with scores from high to low output, b) output is unqualified student id information, c) can query result,
For the physical fitness test to design the corresponding data structure (logical structure and storage structure), and can efficiently complete several requirements,
Design two query modes, write the corresponding logical structure and storage structure, describe and compare their query efficiency,
Write the algorithm performs a) required