將一個n元一維向量向左翻轉i個位置的演算法（二）

def reverseArr2[T](n:Int, arr:Array[T])={<br />def inverseVector[S](start:Int, end: Int,arr:Array[S])={<br />val pair = (end - start)/2<br />val sum = start + end - 1<br />var j = start<br />for (i <- 1 to pair){<br />val t = arr(j)<br />arr(j) = arr(sum - j)<br />arr(sum - j) = t</p><p>j += 1<br />}<br />arr<br />}<br />inverseVector(0,n,arr)<br />inverseVector(n,arr.size,arr)<br />inverseVector(0,arr.size,arr)<br />}