Compilare: user.cpp: In function ‘int main()’: user.cpp:19:9: warning: unused variable ‘prec’ [-Wunused-variable] pct prec,act,prim; ^ user.cpp:19:14: warning: unused variable ‘act’ [-Wunused-variable] pct prec,act,prim; ^ user.cpp:19:18: warning: unused variable ‘prim’ [-Wunused-variable] pct prec,act,prim; ^ user.cpp:20:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("aria.in","r",stdin); ^ user.cpp:21:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("aria.out","w",stdout); ^ user.cpp:22:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:23:53: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=0;i<n;i++) scanf("%lf%lf",&p[i].x,&p[i].y); ^