/in/foo.cc: In function 'int main()':
/in/foo.cc:16:42: error: 'strcpy_s' was not declared in this scope
   if (duicheng(b) == 0) { strcpy_s(a[i],b); n++; }
                                          ^
/in/foo.cc:24:20: error: 'strcpy_s' was not declared in this scope
     strcpy_s(c,a[k]);
                    ^