Compilare: user.cpp: In function ‘int main()’: user.cpp:12:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen("perm2.in","r",stdin); ^ user.cpp:13:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("perm2.out","w",stdout); ^ user.cpp:14:16: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n);for(i=1;i<=n;i++) scanf("%d",&p[i]); ^ user.cpp:14:52: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n);for(i=1;i<=n;i++) scanf("%d",&p[i]); ^