View Compilation Error

0_0_39542150_41.cpp: In member function 'void Fenwick::init(int)':
0_0_39542150_41.cpp:14:32: error: 'i' was not declared in this scope
   14 |     void init(int _n){n=_n;rep(i,0,n)a[i]=0;}
      |                                ^
0_0_39542150_41.cpp:14:28: error: 'rep' was not declared in this scope; did you mean 'frexp'?
   14 |     void init(int _n){n=_n;rep(i,0,n)a[i]=0;}
      |                            ^~~
      |                            frexp
0_0_39542150_41.cpp: In function 'void solve()':
0_0_39542150_41.cpp:89:22: error: 'struct Fenwick' has no member named 'sum'
   89 |         ans[id] = tr.sum(in[rt], out[rt]);
      |                      ^~~