Compilare: main.cpp: In function 'int main()': main.cpp:20:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<s.size(); ++i) ~^~~~~~~~~ main.cpp:44:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<stiva.size();++k) ~^~~~~~~~~~~~~ main.cpp:63:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<ans.size();++i) ~^~~~~~~~~~~