Compilare: main.cpp: In function 'int main()': main.cpp:90:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 90 | for(int i=2;i<=levels.size();i++) | ~^~~~~~~~~~~~~~~ main.cpp:96:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 96 | for(int i=1;i<=levels.size();i++) | ~^~~~~~~~~~~~~~~ main.cpp:99:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 99 | for(int i=1;i<=levels.size()-(1<<j)+1;i++) | ~^~~~~~~~~~~~~~~~~~~~~~~~