View Compilation Error

0_0_24624417_13699.cpp: In function 'int main()':
0_0_24624417_13699.cpp:21:35: error: invalid conversion from 'int' to 'void*' [-fpermissive]
             memset(c, 0, sizeof(c));
                                   ^
In file included from GCC4.9.2/x86_64-w64-mingw32/include/c++/cstring:42:0,
                 from 0_0_24624417_13699.cpp:3:
GCC4.9.2/x86_64-w64-mingw32/include/string.h:43:18: note: initializing argument 1 of 'void* memset(void*, int, size_t)'
   void * __cdecl memset(void *_Dst,int _Val,size_t _Size);
                  ^