Compilare: user.cpp: In function ‘int main()’: user.cpp:37:11: warning: unused variable ‘vf’ [-Wunused-variable] int i,vf,k=0; ^~ user.cpp:37:14: warning: unused variable ‘k’ [-Wunused-variable] int i,vf,k=0; ^ user.cpp:38:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&n); ^ user.cpp:40:41: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d",&v[i].x,&v[i].y); ^