using System;
class Program
{
static void Swap<T> (ref T a, ref T b) {
T temp = a;
a = b;
b = temp;
}
static void Main() {
int[] arr = new int[] {99, 3, 7, 0, 2, 1, 8, 6};
Swap(ref arr[0], ref arr[4]);
for (int i = 0; i < arr.Length; i++) {
Console.Write(arr[i] + " ");
}
}
}
/*
run:
2 3 7 0 99 1 8 6
*/