combo.cpp:16:28: error: 'vector' has not been declared
16 | void add_next(string &cur, vector<char> &avail, int &now, int N);
| ^~~~~~
combo.cpp:16:34: error: expected ',' or '...' before '<' token
16 | void add_next(string &cur, vector<char> &avail, int &now, int N);
| ^
combo.cpp:17:1: error: expected unqualified-id before '{' token
17 | {
| ^
combo.cpp: In function 'std::string guess_sequence(int)':
combo.cpp:28:3: error: 'vector' was not declared in this scope
28 | vector<char> vv = {'A', 'B', 'X', 'Y'};
| ^~~~~~
combo.cpp:2:1: note: 'std::vector' is defined in header '<vector>'; did you forget to '#include <vector>'?
1 | #include "combo.h"
+++ |+#include <vector>
2 | using namespace std;
combo.cpp:28:10: error: expected primary-expression before 'char'
28 | vector<char> vv = {'A', 'B', 'X', 'Y'};
| ^~~~
combo.cpp:29:10: error: expected primary-expression before 'char'
29 | vector<char> avail;
| ^~~~
combo.cpp:31:18: error: 'vv' was not declared in this scope
31 | for (char ch : vv) if (ch != first) avail.push_back(ch);
| ^~
combo.cpp:31:39: error: 'avail' was not declared in this scope
31 | for (char ch : vv) if (ch != first) avail.push_back(ch);
| ^~~~~
combo.cpp:34:17: error: 'avail' was not declared in this scope
34 | add_next(cur, avail, now, N);
| ^~~~~