Wrong Answer
/in/foo.cc: In function 'int main()':
/in/foo.cc:12:16: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[5001]' [-Wformat=]
scanf("%s",&a); // 读入序列，存入数组a
^
/in/foo.cc: In function 'int main()':
/in/foo.cc:12:16: warning: format '%s' expects argument of type 'char*', but argument 2 has type 'char (*)[5001]' [-Wformat=]
scanf("%s",&a); // 读入序列，存入数组a
^
