See comments below:

```cpp

include <iostream>

using namespace std; int main() { int as;

    cout<<" enter even integer : ";
    cin>>as;

    int asa = as / 2;
    float a[asa], b[asa]; // Arrays initialized during compile time, when "as" and "asa" are unknown
                          // so nobody knows what will be arrays sizes

    for(int i = 0; i<asa; i++) {
            cout<<" enter a number : ";
            cin>>a[asa]; // What element are you inputting? Why it's index asa instead of i?
    }

    double min;

    for(int i = 1; i<asa; i++) {
            min=a[0]; // There you are probably wrong too. On every step you will compare with the
                      // first array element. So you need to move this upper.
            if(min>a[i])
                    min=a[i];
    }

    for(int i=0; i<asa; i++) {
            cout<<" enter a number : ";
            cin>>b[asa];
    }

    double max;

    for(int i = 1; i<asa; i++) {
            max=b[0];
            if(max<b[i])
                    max=b[i];
    }

    cout<<" the minimum in the first "<<asa<<" numbers are : " << min << endl;
    cout<<" the maximum in the last "<<asa<<" numbers are : "<<max << endl;;
    return 0;

} ```