Compilare: user.cpp: In function ‘int main()’: user.cpp:12:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secv2.in", "rt", stdin); ^ user.cpp:13:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secv2.out", "wt", stdout); ^ user.cpp:14:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &N, &k); ^ user.cpp:21:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^ user.cpp:35:28: warning: ‘right’ may be used uninitialized in this function [-Wmaybe-uninitialized] cout << left << ' ' << right << ' ' << ans << '\n'; ^ user.cpp:35:13: warning: ‘left’ may be used uninitialized in this function [-Wmaybe-uninitialized] cout << left << ' ' << right << ' ' << ans << '\n'; ^