一道有难度的C语言题目 帮帮忙 写下 会追加分数

Modify  the  program from question 1 so that it does the following
 
 Prompt the user for an action   (U (update), P(print),  C (clear), Q(quit));  
 
 U -  it asks for  student  ID and mark and call update       // this is already done 
 
 P -  calls a printmarks function, which  outputs the list of students and their marks, one per line.   
 
 C -  Ask for a student number and clears their marks. If the student number starts with '0', it clears all marks. 
 
 Q - The program terminate

答案：源代码贴出来，不然做了也是白做，不一定符合你的接口。

其他：让你在问题1的基础上修改代码，问题1呢？ 

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