Compilare: user.cpp: In function ‘int main()’: user.cpp:56:72: warning: suggest parentheses around assignment used as truth value [-Wparentheses] for (int i=1; i<=n; i++) v[i].clear(), lvl[i] = u[i] = high[i] = 0; ~~~~~~~~^~~ user.cpp:66:23: warning: unused variable ‘x’ [-Wunused-variable] for (int i=1, x, y; i<=k; i++){ ^ user.cpp:66:26: warning: unused variable ‘y’ [-Wunused-variable] for (int i=1, x, y; i<=k; i++){ ^