Compilare: user.cpp: In function ‘int main()’: user.cpp:30:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secv3.in", "r", stdin); ^ user.cpp:31:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("secv3.out", "w", stdout); ^ user.cpp:33:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &l, &u); ^ user.cpp:35:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^ user.cpp:37:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &b[i]); ^ user.cpp:47:9: warning: ‘last’ may be used uninitialized in this function [-Wmaybe-uninitialized] printf("%.2f", (double)last / 100); ^