public func solution(_A : [Int]) ->Int{
var argMin :Double=Double((A[0] + A[1])/2)
var arg2 :Double=0
var arg3 :Double=0
var minIndex :Int=0
for I in 0..A.count - 2
arg2 =Double((Double(A[i]) +Double(A[i +1]))/2)
arg3 =Double((Double(A[i]) +Double(A[i +1]) +Double(A[i +2]))/3)
if arg2 < argMin {
argMin = arg2
minIndex = i
}
if arg3 < argMin {
argMin = arg3
minIndex = i
}
}
if (Double(Double(A[A.count-1]) +Double(A[A.count-2]))/2) < argMin {
minIndex = A.count-2
}
return minIndex
}