View Compilation Error

0_0_29881522_27559.cpp: In function 'void build(ll, ll, ll)':
0_0_29881522_27559.cpp:17:11: error: 'tr' was not declared in this scope
     ++pp; tr[rt].l = l; tr[rt].r = r;
           ^
0_0_29881522_27559.cpp: In function 'void cr(ll, ll)':
0_0_29881522_27559.cpp:28:15: error: 'tr' was not declared in this scope
     ll mid = (tr[rt].l + tr[rt].r) >> 1;
               ^
0_0_29881522_27559.cpp: In function 'll ch(ll, ll, ll)':
0_0_29881522_27559.cpp:43:9: error: 'tr' was not declared in this scope
     if (tr[x].l == tr[x].r)
         ^
0_0_29881522_27559.cpp:45:14: error: 'tr' was not declared in this scope
     ll tmp = tr[tr[y].ls].sum - tr[tr[x].ls].sum;
              ^