Compilare: user.cpp: In function ‘int main()’: user.cpp:7:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("expresie.in","r",stdin); ^ user.cpp:8:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("expresie.out","w",stdout); ^ user.cpp:9:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&n); ^ user.cpp:10:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d ",&v[1]); ^ user.cpp:14:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i]); ^ user.cpp:22:19: warning: ‘unu’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(int i=unu-1;i<=n;i++) ^