Compilare: user.cpp: In function ‘int main()’: user.cpp:8:15: warning: unused variable ‘k’ [-Wunused-variable] int n,i,j,k,o; ^ user.cpp:8:17: warning: unused variable ‘o’ [-Wunused-variable] int n,i,j,k,o; ^ user.cpp:9:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^ user.cpp:11:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&v[i]); ^