View Compilation Error

0_0_39499619_875.cpp: In function 'int main()':
0_0_39499619_875.cpp:97:9: error: 'memset' was not declared in this scope
   97 |         memset(son, 0, sizeof son);
      |         ^~~~~~
0_0_39499619_875.cpp:3:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    2 | #include <set>
  +++ |+#include <cstring>
    3 | #define int long long