library.cpp: In function 'void Solve(int)':
library.cpp:15:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
15 | for (int i = 0; i < left.size(); ++i) {
| ~~^~~~~~~~~~~~~
library.cpp:24:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
24 | for (int i = 0; i < left.size(); ++i) if (left[i] == l) ind = i;
| ~~^~~~~~~~~~~~~
library.cpp:34:3: error: 'reverse' was not declared in this scope
34 | reverse(back.begin(), back.end());
| ^~~~~~~