Compilare: user.cpp: In function ‘void prefix(std::string)’: user.cpp:19:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<p.size();i++) ^ user.cpp: In function ‘int kmp(int, int)’: user.cpp:30:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ^ user.cpp:34:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(k==v[j].size()-1) ^ user.cpp: In function ‘void solve()’: user.cpp:48:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<s.size();i++) ^