Owl Get a Life

Compile Error

sadtrainer2.cpp: In function ‘int main()’:
sadtrainer2.cpp:26:7: error: ‘A’ was not declared in this scope
26 | tree<A, null_type,less<A>, rb_tree_tag,tree_order_statistics_node_update> present;
| ^
sadtrainer2.cpp:26:74: error: template argument 1 is invalid
26 | tree<A, null_type,less<A>, rb_tree_tag,tree_order_statistics_node_update> present;
| ^
sadtrainer2.cpp:26:74: error: template argument 3 is invalid
sadtrainer2.cpp:27:10: error: request for member ‘reserve’ in ‘present’, which is of non-class type ‘int’
27 | present.reserve(present_n);
| ^~~~~~~
sadtrainer2.cpp:34:11: error: request for member ‘insert’ in ‘present’, which is of non-class type ‘int’
34 | present.insert(trainer);
| ^~~~~~
sadtrainer2.cpp:42:15: error: request for member ‘find’ in ‘present’, which is of non-cla