Compilare: user.cpp: In function ‘void build(int, int, int)’: user.cpp:22:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i1 < A[2*nod].size() && i2 < A[2*nod+1].size()) { ^ user.cpp:22:61: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i1 < A[2*nod].size() && i2 < A[2*nod+1].size()) { ^ user.cpp:31:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (;i1<A[2*nod].size();i1++) ^ user.cpp:34:34: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (;i2<A[2*nod+1].size();i2++) ^