0_0_29014529_10018.cpp: In function 'int main()': 0_0_29014529_10018.cpp:8:38: error: 'memset' was not declared in this scope #define mem(a,b) memset(a,b,sizeof(a)) ^ 0_0_29014529_10018.cpp:38:3: note: in expansion of macro 'mem' mem(c, 0); ^