foo.cc:14:1: error: ‘vector’ does not name a type
   14 | vector<array<int, 3>> v;
      | ^~~~~~
foo.cc: In function ‘void solve()’:
foo.cc:43:9: error: ‘v’ was not declared in this scope
   43 |         v.push_back({i, l, r});
      |         ^
foo.cc:50:10: error: ‘v’ was not declared in this scope
   50 |     sort(v.begin(), v.end(), cmp);
      |          ^
foo.cc:53:20: error: ‘r’ was not declared in this scope
   53 |         while (i < r) adds(a[++ i], res);
      |                    ^
foo.cc:54:20: error: ‘r’ was not declared in this scope
   54 |         while (i > r) del(a[i --], res);
      |                    ^
foo.cc:55:20: error: ‘l’ was not declared in this scope
   55 |         while (j < l) del(a[j ++], res);
      |                    ^
foo.cc:56:20: error: ‘l’ was not declared in this scope
   56 |         while (j > l) adds(a[-- j], res);
      |                    ^