Codility MinAvgTwoSlice (min_avg_two_slice) - Solved in Go

func Solution(A []int) int {
    n := len(A) - 1
    min := float64(0);
    pos := -1;
    for i := 0; i < n; i++ {
        avg2 := float64(A[i] + A[i + 1]) / 2;
        avg := avg2;
        if i + 2 <= n {
            avg3 := float64(A[i] + A[i + 1] + A[i + 2]) / 3;
            if avg > avg3 {
                avg = avg3
            }
        }
        if avg < min || pos < 0 {
            min = avg;
            pos = i
        }
    }
    return pos;
}