View Compilation Error

0_0_38573695_21926.cpp: In function 'int main()':
0_0_38573695_21926.cpp:2:18: error: 'memset' was not declared in this scope
 #define mem(a,n) memset(a,n,sizeof(a))
                  ^~~~~~
0_0_38573695_21926.cpp:37:9: note: in expansion of macro 'mem'
         mem(vis, 0);
         ^~~
0_0_38573695_21926.cpp:2:18: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
+#include <cstring>
 #define mem(a,n) memset(a,n,sizeof(a))
                  ^~~~~~
0_0_38573695_21926.cpp:37:9: note: in expansion of macro 'mem'
         mem(vis, 0);
         ^~~