Compilare: user.cpp: In function ‘int main()’: user.cpp:24:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); ++i) ^ user.cpp:41:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = n; i < sir.size(); ++i) { ^ user.cpp:41:23: warning: ‘n’ may be used uninitialized in this function [-Wmaybe-uninitialized] for (int i = n; i < sir.size(); ++i) { ^