c++ - truncated integer division removal

Question

How do T avoid truncated integer division in this code? My sorted array is 1 1 1 1 1 1, so a[0] = 1 and a[n] should be 1 / 2 = 0.5.

int main()
{
    long long n,w;
    scanf("%lld %lld", &n, &w);
    long long arr[2*n];
    for(long long i = 0; i < 2 * n; i++)
    {
      scanf("%lld", &arr[i]);
    }
    sort(arr,arr+2*n);

    long long a = arr[0];
    long long b = (float)(arr[n]/2); // <--- this part of code
    cout << " a is " << a << endl;
    cout << " b is " << b << endl;
    long long m = min(a,b);
    cout << " m is " << m << endl;
    long long and = min(m * n + m * 2LL * n, w);
    printf("%lld", ans);
    return 0;
}

Answer 1

The b variable cannot hold a floating point number since it is an integer. Not only your conversion to float happens too late, but you store the result in an integer variable. How could you expect something else than a integer result ?

float b = ((float)arr[n])/2.f;

Would give better results.