Compilare: user.cpp: In function ‘int main()’: user.cpp:21:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int p = 0; p < exp.size(); ++p) { ^ user.cpp:31:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int p = 0; p < exp.size(); ++p) ^ user.cpp:32:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int q = p; q < exp.size(); ++q) ^ user.cpp:38:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int q = p; q < exp.size(); ++q) { ^ user.cpp:43:20: warning: variable ‘nr’ set but not used [-Wunused-but-set-variable] int nr = 0; ^ user.cpp:20:11: warning: unused variable ‘last’ [-Wunused-variable] int last = -1; ^