View Compilation Error

0_0_39519847_7616.cpp: In function 'int main()':
0_0_39519847_7616.cpp:17:17: error: 'memset' was not declared in this scope
   17 |                 memset(anc,-1,sizeof(anc));
      |                 ^~~~~~
0_0_39519847_7616.cpp:3:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    2 | #include<iostream>
  +++ |+#include <cstring>
    3 | #define RI register int