Compilare: user.cpp: In function ‘int main()’: user.cpp:24:18: warning: unused variable ‘tx’ [-Wunused-variable] int n,i,nr=0,tx,ty,rez=0,num=1,j; ^ user.cpp:24:21: warning: unused variable ‘ty’ [-Wunused-variable] int n,i,nr=0,tx,ty,rez=0,num=1,j; ^ user.cpp:22:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trapez.in","r",stdin); ^ user.cpp:23:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("trapez.out","w",stdout); ^ user.cpp:25:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&n); ^ user.cpp:27:38: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&v[i].x,&v[i].y); ^