Compilare: user.cpp: In function ‘int main()’: user.cpp:47:5: warning: variable ‘db’ set but not used [-Wunused-but-set-variable] lf db; ^ user.cpp:33:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secv4.in", "r", stdin); ^ user.cpp:34:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secv4.out", "w", stdout); ^ user.cpp:36:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] R("%d%d%d", &n, &x, &y); ^ user.cpp:38:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] R("%lf", &v[i]); ^ user.cpp:81:18: warning: ‘dr’ may be used uninitialized in this function [-Wmaybe-uninitialized] cout << dr - st << " " << st + 1; ^ user.cpp:81:18: warning: ‘st’ may be used uninitialized in this function [-Wmaybe-uninitialized]