Compilare: user.cpp: In function ‘void ap()’: user.cpp:30:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,a=x.size(),pi,p; ^ user.cpp: In function ‘void mp()’: user.cpp:66:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘int main()’: user.cpp:85:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<x.size();i++) ^