answer.code:66:45: error: elements of array ‘std::tuple<long long int, long long int, long long int> a [400040]’ have incomplete type
   66 | std::tuple<long long, long long, long long> a[4 * M];
      |                                             ^
answer.code:66:45: error: storage size of ‘a’ isn’t known
answer.code: In function ‘int main()’:
answer.code:88:21: error: ‘make_tuple’ is not a member of ‘std’
   88 |         a[i] = std::make_tuple(det(A - Q[i], B - Q[i]), (A - Q[i]).len2(), (B - Q[i]).len2());
      |                     ^~~~~~~~~~
answer.code:5:1: note: ‘std::make_tuple’ is defined in header ‘<tuple>’; did you forget to ‘#include <tuple>’?
    4 | #include <vector>
  +++ |+#include <tuple>
    5 | 
answer.code:72:10: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   72 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
answer.code:75:14: warning: ignoring return value of ‘int scanf(const char*, ...)’ declared with attribute ‘warn_unused_result’ [-Wunused-result]
   75 |         scanf("%lld %lld", &x, &y);
      |         ~~~~~^~~~~~~~~~~~~~~~~~~~~