strange_device.cpp: In function 'int main()':
strange_device.cpp:14:23: warning: comparison of integer expressions of different signedness: 'int' and 'ull' {aka 'long long unsigned int'} [-Wsign-compare]
14 | for (int i = 0; i < n; i++) {
| ~~^~~
strange_device.cpp:23:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long unsigned int, long long unsigned int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
23 | for (int i = 0; i < v.size();) {
| ~~^~~~~~~~~~
strange_device.cpp:25:48: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long unsigned int, long long unsigned int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
25 | for (; v[i].second >= v[j].second && j < v.size(); j++);
| ~~^~~~~~~~~~