Compilare: main.cpp: In function 'void dfs(int, int, int)': main.cpp:26:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 26 | for (i = 0; i * 2 + 1 < back[nod].size(); i++) { | ~~~~~~~~~~^~~~~~~~~~~~~~~~~~ main.cpp:31:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare] 31 | if (i * 2 < back[nod].size()) { | ~~~~~~^~~~~~~~~~~~~~~~~~ main.cpp:11:9: warning: unused variable 'last' [-Wunused-variable] 11 | int last = 0, x = 0; | ^~~~ main.cpp:11:19: warning: unused variable 'x' [-Wunused-variable] 11 | int last = 0, x = 0; | ^ main.cpp: In function 'int main()': main.cpp:54:20: 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] 54 | if (ans.size() != m / 2) { | ~~~~~~~~~~~^~~~~~~~