Compilare: user.cpp: In function ‘int main()’: user.cpp:9:37: 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:10:39: 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:13:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:17:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&v[i]); ^ user.cpp:27:50: warning: ‘i3’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(i!=i3 && i!=i3+1 && i!=i3+2) s+=v[i]; ^ user.cpp:34:30: warning: ‘i1’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(i!=i1 && i!=i1+1 && i!=i2 && i!=i2+1) s+=v[i]; ^ user.cpp:34:50: warning: ‘i2’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(i!=i1 && i!=i1+1 && i!=i2 && i!=i2+1) s+=v[i]; ^