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("permut.in", "r", 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("permut.out", "w", stdout); ^ user.cpp:15:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:16:54: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i = 0; i < n; ++i) scanf("%d", &first[i]); ^ user.cpp:17:55: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(int i = 0; i < n; ++i) scanf("%d", &second[i]); ^