Compilare: user.cpp: In function ‘void lee(int)’: user.cpp:15:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[k].size();i++) ^ user.cpp: In function ‘void lee1(int)’: user.cpp:30:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b[k].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:68:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<a[i].size();j++) ^ user.cpp:99:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<b[i].size();j++) ^