Compilare: user.cpp: In function ‘void solve()’: user.cpp:81:10: warning: variable ‘ok_2’ set but not used [-Wunused-but-set-variable] bool ok_2 = false; ^ user.cpp: In function ‘void read()’: user.cpp:43:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:48:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^