View Compilation Error

0_0_39465522_29657.cpp: In function 'int main()':
0_0_39465522_29657.cpp:4:5: error: 'function' was not declared in this scope; did you mean 'union'?
    4 |     function<void(int, int)> cdq = [&](int l, int r) {
      |     ^~~~~~~~
      |     union
0_0_39465522_29657.cpp:4:27: error: expression list treated as compound expression in functional cast [-fpermissive]
    4 |     function<void(int, int)> cdq = [&](int l, int r) {
      |                           ^
0_0_39465522_29657.cpp:4:14: error: expected primary-expression before 'void'
    4 |     function<void(int, int)> cdq = [&](int l, int r) {
      |              ^~~~
0_0_39465522_29657.cpp:12:27: error: 'n' was not declared in this scope
   12 |     long long ans = 1ll * n * (n - 1) * (n - 2) / 6;
      |                           ^
0_0_39465522_29657.cpp:14:5: error: 'cout' was not declared in this scope
   14 |     cout << ans;
      |     ^~~~