Compilare: main.cpp: In function 'void construct(std::__cxx11::string, std::__cxx11::string)': main.cpp:22:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ind<s.size() and s.size()-1-ind+1>0) ~~~^~~~~~~~~ main.cpp:46:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(last<s.size() and ind-last+1>0) ~~~~^~~~~~~~~ main.cpp:49:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ind<s.size() and s.size()-1-ind+1>0) ~~~^~~~~~~~~ main.cpp: In function 'int main()': main.cpp:63:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<v.size();++i) ~^~~~~~~~~