View Compilation Error

0_0_39447863_31506.cpp: In function 'void solve()':
0_0_39447863_31506.cpp:116:25: error: 'memset' was not declared in this scope
  116 |                         memset(mark, 0, sizeof mark);
      |                         ^~~~~~
0_0_39447863_31506.cpp:6:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    5 | #include<algorithm>
  +++ |+#include <cstring>
    6 | using namespace std;