0_0_16952878_19768.cpp: In function 'int main()': 0_0_16952878_19768.cpp:6:37: error: 'memset' was not declared in this scope #define mem(a); memset(a,0,sizeof(a)); ^ 0_0_16952878_19768.cpp:54:3: note: in expansion of macro 'mem' mem(a);k=flag=0; ^