Compilare: user.cpp: In function ‘void update(int, int, int)’: user.cpp:37:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<a[(nod<<1)].size() && j<a[(nod<<1)+1].size()) ^ user.cpp:37:56: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<a[(nod<<1)].size() && j<a[(nod<<1)+1].size()) ^ user.cpp:50:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(i<a[(nod<<1)].size()) ^ user.cpp:55:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j<a[(nod<<1)+1].size()) ^ user.cpp: In function ‘int main()’: user.cpp:223:17: warning: unused variable ‘nod’ [-Wunused-variable] int st, dr, nod, i, j, m, x1, y1, y2, x2; ^ user.cpp:223:25: warning: unused variable ‘j’ [-Wunused-variable] int st, dr, nod, i, j, m, x1, y1, y2, x2; ^