tickets.cpp: In function 'll find_answer(std::vector<long long int>)':
tickets.cpp:21:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
21 | for (int i = 0; i < a.size(); i++) {
| ~~^~~~~~~~~~
tickets.cpp:23:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
23 | for (int j = 0; j < a.size(); j++) {
| ~~^~~~~~~~~~
tickets.cpp: In function 'll find_maximum(int, std::vector<std::vector<int> >)':
tickets.cpp:48:1: warning: control reaches end of non-void function [-Wreturn-type]
48 | }
| ^