选择排序真题.doc

11.【加试题】有如下程序段:
For i = 1 To 2
For j = 5 To i + 1 Step -1
If a(j) > a(i) Then
t = a(j): a(j) = a(i): a(i) = t
End If
Next j
Next i
数组元素a(1)到a(5)的值依次为“33,24,45, ,16,77”,经过该程序段“加工”后,数组元素a(1)到a(5)的值依次为
A. 77,45,33,16,24 B. 77,33,45,16,24
C. 77,24,45,16,33 D. 77,45,33,24,16
12.【加试题】小赵对选择排序算法进行了如下改进:在数组的所有元素中找出最小和最大数据的元素,然后将这两个元素分别与第一个和最后一个元素交换数据,在余下的元素中找出最小和最大数据的元素,分别与第二个和倒数第二个元素交换数据,以此类推,直到所有元素的数据按升序排列。小赵编写的VB程序段如下:
p = 1: q = 10
Do While p < q
iMin = p: iMax = p
For i = p + 1 To q
If a(i) < a(iMin) Then iMin = i
If a(i) > a(iMax) Then iMax = i
Next i
t = a(iMin): a(iMin) = a(p): a(p) = t
①
t = a(iMax): a(iMax) = a(q): a(q) = t
p = p + 1
q = q - 1
Loop
要使程序实现上述算法思想,则方框中的语句是
iMax = p Then iMax = iMin
iMin = p Then iMin = iMax
iMax = p Then iMin = iMax
iMin = p Then iMax = iMin