Main.cc: In function ‘int main()’:
Main.cc:8:14: error: ‘a’ was not declared in this scope
cin>>a[i];
^
Main.cc:22:20: error: ‘a’ was not declared in this scope
ar=abs(a[i]-av);
^
Main.cc:6:11: warning: unused variable ‘num’ [-Wunused-variable]
float num[n],min=1000,max=0,mini=0,maxi=0,av,ar,armax=0;
^~~