Compilare: user.cpp: In function ‘int main()’: user.cpp:7:9: warning: unused variable ‘val’ [-Wunused-variable] int val; ^ user.cpp:12:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^ user.cpp:18:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&a[i]); ^ user.cpp:26:22: warning: ‘sum’ may be used uninitialized in this function [-Wmaybe-uninitialized] sum+=a[i]; ^