View Compilation Error

0_0_14160385_8649.cpp: In function 'int main()':
0_0_14160385_8649.cpp:24:35: error: invalid conversion from 'long long unsigned int' to 'void*' [-fpermissive]
         memset((ans,0,sizeof(ans)));
                                   ^
0_0_14160385_8649.cpp:24:35: error: too few arguments to function 'void* memset(void*, int, size_t)'
In file included from 0_0_14160385_8649.cpp:3:0:
GCC4.9.2/x86_64-w64-mingw32/include/string.h:43:18: note: declared here
   void * __cdecl memset(void *_Dst,int _Val,size_t _Size);
                  ^
0_0_14160385_8649.cpp:35:25: error: 'mod' was not declared in this scope
                 ans[j]%=mod;
                         ^