Compilare: main.cpp: In function 'bool dfs(int, int)': main.cpp:31:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | for(int i = 0; i + 1 < free.size(); i += 2) | ~~~~~~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:60:19: warning: comparison of integer expressions of different signedness: 'std::vector<std::tuple<int, int, int> >::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare] 60 | if(ans.size() == m / 2) | ~~~~~~~~~~~^~~~~~~~