Language: C++

#include "bits/stdc++.h"
#include<unordered_map>
#include<unordered_set>
#pragma warning(disable:4996)
using namespace std;
using ld = long double;
const ld eps = 1e-9;

struct tree {
	int value;
	unique_ptr<tree>ltree, rtree;
	tree(const int value_):value(value_) {

	}

};
void ins(unique_ptr<tree>&t, int num) {
	if (t == nullptr) {
		t = make_unique<tree>(num);
	}
	else {
		if (num < t->value) {
			ins(t->ltree, num);
		}
		else {
			ins(t->rtree, num);
		}
	}
}
bool fi(unique_ptr<tree>&t, int num) {
	if (t == nullptr)return false;
	else {
		if (num == t->value)return true;
		else if (num < t->value) {
			return find(t->ltree, num);
		}
		else {
			return find(t->rtree, num);
		}
	}
}
void dfs(unique_ptr< tree>&t,bool mid,vector<int>&v) {
	if (mid) {
		v.emplace_back(t->value);
	}
	if (t->ltree) {
		dfs(t->ltree, mid, v);
	}
	if (!mid) {
		v.emplace_back(t->value);
	}
	if (t->rtree) {
		dfs(t->rtree, mid, v);
	}
	
	return;
}

int main() {
	int N; cin >> N;
	unique_ptr<tree> t(nullptr);
	while (N--) {
		string st;  cin >> st ;
		if (st == "print") {
			vector<int> v;
			for (int i = 0; i < 2; ++i) {
				dfs(t, bool(i), v);
				cout << " ";
				for (int i = 0; i < v.size(); ++i) {
					cout << v[i];
					if (i == v.size() - 1)cout << endl;
					else cout << " ";
				}
				v.clear();
			}
			
		}
		else if(st=="insert") {
			int a; cin >> a;
			ins(t, a);
		}
		else {
			int a; cin >> a;
			bool ok = fi(t, a);
			if (ok)cout << "yes" << endl;
			else cout << "no" << endl;
		}
	}
	return 0;
}

Compiler output:
a.cc: In function 'bool fi(std::unique_ptr<tree>&, int)':
a.cc:35:36: error: no matching function for call to 'find(std::unique_ptr<tree>&, int&)'
   35 |                         return find(t->ltree, num);
      |                                ~~~~^~~~~~~~~~~~~~~
In file included from /usr/include/c++/14/algorithm:61,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:51,
                 from a.cc:1:
/usr/include/c++/14/bits/stl_algo.h:3842:5: note: candidate: 'template<class _IIter, class _Tp> _IIter std::find(_IIter, _IIter, const _Tp&)'
 3842 |     find(_InputIterator __first, _InputIterator __last,
      |     ^~~~
/usr/include/c++/14/bits/stl_algo.h:3842:5: note:   candidate expects 3 arguments, 2 provided
In file included from /usr/include/c++/14/algorithm:86:
/usr/include/c++/14/pstl/glue_algorithm_defs.h:60:1: note: candidate: 'template<class _ExecutionPolicy, class _ForwardIterator, class _Tp> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, _ForwardIterator> std::find(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, const _Tp&)'
   60 | find(_ExecutionPolicy&& __exec, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value);
      | ^~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:60:1: note:   candidate expects 4 arguments, 2 provided
In file included from /usr/include/c++/14/iterator:66,
                 from /usr/include/x86_64-linux-gnu/c++/14/bits/stdc++.h:54:
/usr/include/c++/14/bits/streambuf_iterator.h:435:5: note: candidate: 'template<class _CharT2> typename __gnu_cxx::__enable_if<std::__is_char<_CharT2>::__value, std::istreambuf_iterator<_CharT, std::char_traits<_CharT> > >::__type std::find(istreambuf_iterator<_CharT, char_traits<_CharT> >, istreambuf_iterator<_CharT, char_traits<_CharT> >, const _CharT2&)'
  435 |     find(istreambuf_iterator<_CharT> __first,
      |     ^~~~
/usr/include/c++/14/bits/streambuf_iterator.h:435:5: note:   candidate expects 3 arguments, 2 provided
a.cc:38:36: error: no matching function for call to 'find(std::unique_ptr<tree>&, int&)'
   38 |                         return find(t->rtree, num);
      |                                ~~~~^~~~~~~~~~~~~~~
/usr/include/c++/14/bits/stl_algo.h:3842:5: note: candidate: 'template<class _IIter, class _Tp> _IIter std::find(_IIter, _IIter, const _Tp&)'
 3842 |     find(_InputIterator __first, _InputIterator __last,
      |     ^~~~
/usr/include/c++/14/bits/stl_algo.h:3842:5: note:   candidate expects 3 arguments, 2 provided
/usr/include/c++/14/pstl/glue_algorithm_defs.h:60:1: note: candidate: 'template<class _ExecutionPolicy, class _ForwardIterator, class _Tp> __pstl::__internal::__enable_if_execution_policy<_ExecutionPolicy, _ForwardIterator> std::find(_ExecutionPolicy&&, _ForwardIterator, _ForwardIterator, const _Tp&)'
   60 | find(_ExecutionPolicy&& __exec, _ForwardIterator __first, _ForwardIterator __last, const _Tp& __value);
      | ^~~~
/usr/include/c++/14/pstl/glue_algorithm_defs.h:60:1: note:   candidate expects 4 arguments, 2 provided
/usr/include/c++/14/bits/streambuf_iterator.h:435:5: note: candidate: 'template<class _CharT2> typename __gnu_cxx::__enable_if<std::__is_char<_CharT2>::__value, std::istreambuf_iterator<_CharT, std::char_traits<_CharT> > >::__type std::find(istreambuf_iterator<_CharT, char_traits<_CharT> >, istreambuf_iterator<_CharT, char_traits<_CharT> >, const _CharT2&)'
  435 |     find(istreambuf_iterator<_CharT> __first,
      |     ^~~~
/usr/include/c++/14/bits/streambuf_iterator.h:435:5: note:   candidate expects 3 arguments, 2 provided