Compilare: main.cpp: In function 'int pairup(int)': main.cpp:35:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 35 | for(int i = 0; i < v[u].size(); i++) | ~~^~~~~~~~~~~~~ main.cpp:45:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 45 | for(int i = 0; i < v[u].size(); i++) | ~~^~~~~~~~~~~~~ main.cpp: In function 'void solve()': main.cpp:100:18: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 100 | for(i = 0; i < op.size(); i++) | ~~^~~~~~~~~~~