Compilare: user.cpp: In function ‘int main()’: user.cpp:46:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < p1.size(); ++i) cout << p1[i] << " \n"[i == p1.size() - 1]; ^ user.cpp:46:76: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < p1.size(); ++i) cout << p1[i] << " \n"[i == p1.size() - 1]; ^ user.cpp:48:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < p2.size(); ++i) cout << p2[i] << " \n"[i == p2.size() - 1]; ^ user.cpp:48:76: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < p2.size(); ++i) cout << p2[i] << " \n"[i == p2.size() - 1]; ^