Question

vb杨辉三角要求输入n输出第n行

Option Base 1
Private Sub Form_Click()
Dim a%(), b%(), n%, i%, j%
n = Val(InputBox("请输入行数", "杨辉三角"))
Print " 杨辉三角的第 " & n & " 行： "
ReDim Preserve a(1)
ReDim Preserve b(1)
a(1) = 1
b(1) = 1
If n = 1 Then
Print 1
Else
For i = 1 To n
a = b
ReDim Preserve a(i)
ReDim Preserve b(i)
Print b(1);
For j = 2 To i
b(j) = a(j - 1) + a(j)
Print b(j);
Next j
Print
Next i
End If
End Sub

结果输出是n行
但我要输出第n行
怎么改？？

Answer 1

Private Sub Form_Click()
Dim a%(), b%(), n%, i%, j%
n = Val(InputBox("请输入行数", "杨辉三角"))
Print " 杨辉三角的第 " & n & " 行： "
ReDim Preserve a(1)
ReDim Preserve b(1)
a(1) = 1
b(1) = 1
If n = 1 Then
Print 1
Else
For i = 1 To n
a = b
ReDim Preserve a(i)
ReDim Preserve b(i)
If i = n Then Print b(1);
For j = 2 To i
b(j) = a(j - 1) + a(j)
If i = n Then Print b(j);
Next j
Next i
End If
End Sub
共改3个地方：
1 在第17行Print b(1); 前面加个判断if i=n then Print b(1);
2 在第20行Print b(j); 前面加个判断if i=n then Print b(j);
3 将第22行的Print 删掉
好了 这样就应该满足你的需要了

Answer 2

Private Sub Command1_Click()
Dim a%(), i%, j%
n = InputBox("请输入n")
ReDim Preserve a(1 To n, 1 To n)
For i = 1 To n
For j = 1 To i
a(i, j) = 1
a(i, 1) = 1
Next j
Next i
For i = 3 To n
For j = 2 To i - 1
a(i, j) = a(i - 1, j - 1) + a(i - 1, j)
Next j
Next i
For i = 1 To n
For j = 1 To i
If i = n Then Print a(i, j);
Next j
Next i
End Sub