Compilare: user.cpp: In function ‘void FILL(int, int*, int)’: user.cpp:20:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<a[i].size(); ++j){ ~^~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:42:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0; i<a[c].size() && b; ++i){ ~^~~~~~~~~~~~