测试脚本执行速度,输入一个正整数n,用脚本输出从1到n的全部排列顺序
<SCRIPT LANGUAGE=vbscript >
t1=timer()
Dim n
Dim s()
Dim i
Dim j
Dim k
Dim p0
Dim p
Dim cc
n = 6
p0 = 1
For j = 2 To n
p0 = p0 * j
Next
ReDim s(2,p0)
s(0, 0) = 1
s(0, 1) = 1
For i = 2 To n
p = 1
For j = 2 To i
p = p * j
Next
s(1, 0) = p
For k = 1 To s(0, 0)
For j = 1 To i
s(1, i * (k - 1) + j) = Left(s(0, k), j - 1) & i & Right(s(0, k), i - j)
Next
Next
For j = 0 To p
s(0, j) = s(1, j)
Next
Next
cc = s(1, 1)
For i = 2 To p0
cc = cc & "<br/>" & s(1, i)
Next
document.write cc
t2=timer()
msgbox t2-t1
</SCRIPT>
执行时间是:
n=6的时候0.03125
n=7的时候3.9375