求助时间约束条件的代码编写
节约 算 法 又称C-W 算法，是由Clarke和Wright于1964年首次提出的。它的基本思想是首先把各点单独与源点0(车场)相连，构成1条仅含一个点的线路。总费用为两倍的从原点到各点的距离的费用 。然后计算将点i和j连接在一条线路上费用的“节约值”: S(i,j)=c0i+ ci0+ c0j+ cj0-(c0i+ cij+ cj0)= c0i+ c0j-cij S(i,j) 越大，说明把i和i连接在一起时总路程减少越多。构造线路时，根据S(i,j) 从大到小的顺序进行，实现时可在表上操作，具体步骤如下:
Step1: 计算节约值S(i,j) ，并按从大到小顺序排列成表格形式;
Step2:考察表格中最大元素S(i,j) 对应的点i和点j，检查是否满足下列条件:
(1)若 点 i 和点j均不在己构成的线路上，则可连接点i和点j，得到线路段0->i->j->0，转步骤Step3;
(2)若 点 i 或点j在已构成的线路上，但不是线路的内点(即不与源点0直接相连)，则可以连接，连接后得到线路段 ，转步骤Step3;
(3)若 点 i 和点j位于己构成的不同线路上，且均不是内点，则连接后的得到线路段 ，转步骤Step3;
(4)若 点 i和 点j位于已构成的同一条线路上，则不能再进行连接，转步骤Step3；
Step3:划去第i行和第j列，即i点不能再到其他点，而j点也不能由其他点到达;
Step4:若所有元素均被划去，则己得到完整线路，算法终止;否则，在没被划去的元素中选择最大元素，转步骤Step2。
其中的车场0的坐标为（25，90）
其余的客户坐标分别为：（56，72），（10，107），（6，125），（27，79），（18，115）就是在这几个中间进行距离的优化，优化原则是上面所说的c-w算法。不是作业，要给出各部的实现思想也可以。能够给全源码，那当然是感谢咯！
注意，c-w算法不是最优算法，但相当好。
我自己对这个算法的理解不一定和上面给出的一样。请你认真运行检查我下面的代码：
Option Explicit
Private Type point
x As Double
y As Double
End Type
Private Type save
i As Long
j As Long
s As Double
End Type
Private points() As point, cost() As Double, saving() As save, n As Long, m As Long
Private trip() As String
'http://www.
'C-W Saving Algorithm
Private Sub Command1_Click()
Dim i As Long, j As Long, inti As Long, intj As Long, pi As Long, pj As Long, str() As String
ReDim saving((n * (n - 1) / 2)) As save
For i = 1 To n - 1
For j = i + 1 To n
m = m + 1
saving(m).i = i
saving(m).j = j
saving(m).s = cost(0, i) + cost(0, j) - cost(i, j)
Next j
Next i
For i = 1 To m - 1 'sort saving list
For j = i + 1 To m
If saving(j).s > saving(i).s Then
saving(0) = saving(i)
saving(i) = saving(j)
saving(j) = saving(0)
End If
Next j
Next i
Print "Saving:"
For i = 1 To m
Print saving(i).i, saving(i).j, Round(saving(i).s, 2)
Next i
ReDim trip(1 To m)
j = 0
For i = 1 To m
If saving(i).s < 0 Then Exit For
inti = InTrip(saving(i).i & "", pi)
intj = InTrip(saving(i).j & "", pj)
'Create or join trips:
If inti = 0 And intj = 0 Then
j = j + 1
trip(j) = saving(i).i & "-" & saving(i).j
ElseIf inti > 0 And intj = 0 Then
If pi = 1 Then
trip(inti) = saving(i).j & "-" & trip(inti)
ElseIf pi = 2 Then
trip(inti) = trip(inti) & "-" & saving(i).j
End If
ElseIf inti = 0 And intj > 0 Then
If pj = 1 Then
trip(intj) = saving(i).i & "-" & trip(intj)
ElseIf pj = 2 Then
trip(intj) = trip(intj) & "-" & saving(i).i
End If
ElseIf inti <> intj Then 'now inti>0 and intj>0. i and j in different trips. Only join end to end
If pi = 1 And pj = 1 Then
str = Split(trip(inti), "-")
For j = 0 To UBound(str)
trip(intj) = str(j) & "-" & trip(intj)
Next j
trip(inti) = ""
ElseIf pi = 1 And pj = 2 Then
trip(intj) = trip(intj) & "-" & trip(inti)
trip(inti) = ""
ElseIf pi = 2 And pj = 1 Then
trip(intj) = trip(inti) & "-" & trip(intj)
trip(inti) = ""
ElseIf pi = 2 And pj = 2 Then
str = Split(trip(inti), "-")
For j = UBound(str) To 0 Step -1
trip(intj) = trip(intj) & "-" & str(j)
Next j
trip(inti) = ""
End If
End If
Next i
Output
End Sub
Private Function InTrip(node As String, position As Long) As Long
Dim i As Long
For i = 1 To m
If trip(i) <> "" Then
If Left(trip(i), Len(node) + 1) = node & "-" Then 'head of the trip
position = 1
InTrip = i
Exit For
ElseIf Right(trip(i), Len(node) + 1) = "-" & node Then 'tail of the trip
position = 2
InTrip = i
Exit For
ElseIf InStr(trip(i), "-" & node & "-") Then 'middle of the trip
position = 3 'will caurse mistake without this
InTrip = i
Exit For
End If
End If
Next i
End Function
Private Sub Output()
Dim i As Long
Print "Trip:"
For i = 1 To m
If trip(i) <> "" Then
Print "0-" & trip(i) & "-0"
End If
Next i
End Sub
Private Sub Form_Load()
Dim i As Long, j As Long
n = 6 '5
ReDim points(n), cost(0 To n - 1, 1 To n)
Me.AutoRedraw = True
points(0).x = 47 '25
points(0).y = 11 '90
points(1).x = 28 '56
points(1).y = 6 '72
points(2).x = 8 '10
points(2).y = 2 '107
points(3).x = 77 '6
points(3).y = 9 '125
points(4).x = 74 '27
points(4).y = 33 '79
points(5).x = 52 '18
points(5).y = 33 '115
points(6).x = 35
points(6).y = 38
Print "Cost:"
Print "",
For j = 1 To n
Print j,
Next j
For i = 0 To n - 1
Print i,
For j = 1 To i
Print "",
Next j
For j = i + 1 To n 'cost(i,j) is the distance(cost) between i and j
cost(i, j) = Sqr((points(i).x - points(j).x) ^ 2 + (points(i).y - points(j).y) ^ 2)
Print Round(cost(i, j), 2),
Next j
Next i
End Sub
