Compilare: main.cpp: In function 'int main()': main.cpp:11:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<s.size();i++) ~^~~~~~~~~ main.cpp:14:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<s.size() && s[i]==s[j]) ~^~~~~~~~~