Compilare: user.cpp: In function ‘void impa(int, int)’: user.cpp:23:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int a=0;a<na.size();a++) ^ user.cpp: In function ‘void impb(int, int)’: user.cpp:36:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int a=0;a<nb.size();a++) ^ user.cpp: In function ‘int main()’: user.cpp:46:7: warning: suggest parentheses around comparison in operand of ‘&’ [-Wparentheses] if(x==0&sa.size()==0) ^ user.cpp:68:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int a=0;a<sa.size();a++) ^ user.cpp:72:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int a=0;a<sb.size();a++) ^