View Compilation Error

0_0_38953945_8879.cpp: In function 'void solve()':
0_0_38953945_8879.cpp:9:17: error: 'memset' was not declared in this scope
    9 |                 memset(mapp, 0, sizeof mapp);
      |                 ^~~~~~
0_0_38953945_8879.cpp:4:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    3 | #include<algorithm>
  +++ |+#include <cstring>
    4 | #define int long long