View Compilation Error

0_0_16213292_23955.cpp: In function 'int main()':
0_0_16213292_23955.cpp:9:35: error: 'memset' was not declared in this scope
 #define cl(a) memset(a,0,sizeof(a))
                                   ^
0_0_16213292_23955.cpp:53:9: note: in expansion of macro 'cl'
         cl(a);cl(f);
         ^