Compilare: main.cpp: In function 'std::vector<int> eval(std::__cxx11::string)': main.cpp:17:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<str.size();i++){ ~^~~~~~~~~~~ main.cpp:24:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<str.size()){ ~^~~~~~~~~~~ main.cpp:39:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<ot.size();j++){ ~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:58:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<input.size();i++){ ~^~~~~~~~~~~~~ main.cpp:63:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<ot.size();i++){ ~^~~~~~~~~~