Compilare: main.cpp: In function 'int function_solver(std::__cxx11::string, std::__cxx11::string)': main.cpp:112:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<signs.size();++i){ ~^~~~~~~~~~~~~ main.cpp:121:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<signs.size();++i){ ~^~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:154:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1;j<=v.size();++j){ ~^~~~~~~~~~