要求统计并输出一个表格，表格内容包括学号，各课分数，总分和平均分，并标出三门均在90分以上者 实现对两个字符串大小的比较 编程打印出n*n（n＜0）阶的方阵-demand and output a statistical tables, forms, including the contents of the course scores, the total score and average hours and three were marked in 90 hours or more to achieve the size of two strings of programming print n * n (n "0) bands The Lineup