Compilare: user.cpp: In function ‘void update(int, int, int)’: user.cpp:43:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < A[a].size() && j < A[b].size()){ ^ user.cpp:43:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i < A[a].size() && j < A[b].size()){ ^ user.cpp:53:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(;i<A[a].size();i++) ^ user.cpp:55:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(;j<A[b].size();j++) ^