0_0_30343582_9847.cpp: In function 'void first()': 0_0_30343582_9847.cpp:5:38: error: 'memset' was not declared in this scope #define CLR(x) memset(x, 0, sizeof(x)) ^ 0_0_30343582_9847.cpp:36:3: note: in expansion of macro 'CLR' CLR(mp); ^