Compilare: user.cpp: In function ‘int check(int)’: user.cpp:10:14: warning: statement has no effect [-Wunused-value] for(i; i <= n ; ++i) ^ user.cpp:19:14: warning: statement has no effect [-Wunused-value] for(j; j <= n ; ++j){ ^ user.cpp: In function ‘int main()’: user.cpp:34:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("orase1.in", "r", stdin); ^ user.cpp:35:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("orase1.out", "w", stdout); ^ user.cpp:36:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &k); ^ user.cpp:39:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &a[i]); ^