Merge pull request #2 from ds-sww/master

...
size,isEmpty,get,add,remove
fix bugs of remove()
first homework
first commit
修改了文件目录
抽象出了checkSize方法
发现remove忘记返回值了...
hasitu
assignment0 commit by 13307130192(Chen Aidao)
assignment1,2
sync to master
commit by 13301730309
sommit by 13307130309
 writing testcase disability
commit by 13307130309
Merge pull request #1 from ds-sww/master

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assignment3[initial]
Merge pull request #1 from qini7/assignment1

Assignment1
Merge pull request #2 from ds-sww/master

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