View Compilation Error

0_0_38791096_8533.cpp: In member function 'void Tree::clear()':
0_0_38791096_8533.cpp:124:9: error: 'memset' was not declared in this scope
  124 |         memset(last,0,sizeof(last));
      |         ^~~~~~
0_0_38791096_8533.cpp:5:1: note: 'memset' is defined in header '<cstring>'; did you forget to '#include <cstring>'?
    4 | #include<algorithm>
  +++ |+#include <cstring>
    5 | #define rep(i,a,b) for(int i=a;i<=b;++i)
0_0_38791096_8533.cpp: In function 'int main()':
0_0_38791096_8533.cpp:131:25: error: 'struct Tree' has no member named 'G'
  131 |         tree.n = n;tree.G.resize(n+1);
      |                         ^