Compilare: main.cpp: In function 'void dfs(int)': main.cpp:13:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 13 | for(int i = 0; i < v[x].size(); i ++) | ~~^~~~~~~~~~~~~ main.cpp: In function 'void build_levels()': main.cpp:40:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 40 | for(int i = 0; i < v[aux].size(); i ++) | ~~^~~~~~~~~~~~~~~