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there isn't a straightforward formula that yields Fibonacci numbers without iterations; the closest you can get AFAICT is by using Binet's formula (see here[^]) but for large numbers that will be an approximation as it relies on floating-point arithmetic.
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string[] sa=new string('*', (int)Math.Round((Math.Pow(0.5+Math.Sqrt(1.25), n)-Math.Pow(0.5-Math.Sqrt(1.25), n))/Math.Sqrt(5))).Replace("*", ".*").Substring(1).Split('.');
works quite well.
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I suggest you try Fibonacci(100) in a recursive way; you can walk around the world while it computes.
Unless you go for a more advanced equation, one that calculates Fib(2x) from Fib(x).
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Oh, I'm not suggesting that it is a better solution what so ever. I'm just stating it sounds like a homework assignment for creating a recursive Fibonacci implementation. 
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Hi,
recursion is not always the way.
*
*
*
**
***
*****
********
If I were to generate and display the following, you will observe that when n= 50, program
hangs. the number of times recursive method gets called grows exponentially.
In such a case a non recursive method is required.
Regards,
NetQuestions
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Indeed, I'm well aware of such. I was only basing my suggestion on the fact it seemed like a homework assignment to create a recursive method.
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I am not an algorithms expert so mine may be wrong and I did cheat for base case but my recursive Fib algorithm is instant. I won't post because it may be the OP's homework but Fib is not hard and does not require any deep recursion. My algorithm needs 98 levels to calculate the Fib numbers from 2 to 100. (Again, I cheated on the base)
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yes, you can easily avoid the exponential behavior, however I have seen quite a few straightforward recursive implementations that don't. They are extremely good examples against the use of recursion for anything that is not recursive by its very nature (such as a hierarchical file system).
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the number of times the method keeps getting called increases exponentially
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NetQuestions wrote: I want to initialize a string array with "*".
string[] a = new string[] { "*" } ;
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I actually used the following statement
string str = new string('*', 10)
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That doesn't meet the stated criteria.
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I have the following code:
SqlConnection con = new SqlConnection("connection details");
con.Open();
string strSql = "select * from Names";
SqlDataAdapter dadapter = new SqlDataAdapter();
dadapter.SelectCommand = new SqlCommand(strSql, con);
DataSet dset = new DataSet();
dadapter.Fill(dset,"Names");
con.Close();
dataGridView1.DataSource = dset.Tables["Names"];
The dset looks as follows:
ID Name
1 Terence
2 Richard
1. How can I get my datagrid to only show the Name and not the ID column?
2. Also if I have a column named First Name in my datafrid how can I get name to show up in that column and not in a new one or how can I assign custom names to my datagrid?
Any help would be great thanks!
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Thanks for the info , I need the * as I need the ID for other things. I just dont want the ID to appear in the datagrid...
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Using "*" is considered bad practice.
They only reason why you're seeing the ID in the datagrid is because you're relying on it's automatic features to create the columns for you.
If you created the columns and bound them yourself, you get to pick and chose which columns you see in the grid. You've already been given links to the docs and samples that show this.
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Terence van Schalkwyk wrote: 1. How can I get my datagrid to only show the Name and not the ID column?
Like this:
<asp:GridView ID="GridView1" runat="server" AllowPaging="True" AllowSorting="True"
AutoGenerateColumns="False" >
<Columns>
<asp:BoundField DataField="EmployeeID" HeaderText="EmployeeID" ReadOnly="True" SortExpression="EmployeeID" />
<asp:TemplateField HeaderText="EmployeeID" SortExpression="EmployeeID" Visible="false">
</asp:TemplateField>
Terence van Schalkwyk wrote: 2. Also if I have a column named First Name in my datafrid how can I get name to show up in that column and not in a new one or how can I assign custom names to my datagrid?
Similar logic as above.
Success is the good fortune that comes from aspiration, desperation, perspiration and inspiration.
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I am doing it in C# windows application not in asp. Any idea how to do it?
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Terence van Schalkwyk wrote: string strSql = "select * from Names";
1. You could change your query to fetch only the name.
Terence van Schalkwyk wrote: dataGridView1
2. You could hide the first column inside the datagrid by using the visible property of the column.
dataGridView1.Columns(0).Visible = False
Quidquid latine dictum sit, altum videtur.
Whatever is said in Latin sounds profound.
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Abhinav S wrote: 1. You could change your query to fetch only the name.
Not an option as I might need the id elsewhere
Abhinav S wrote: 2. You could hide the first column inside the datagrid by using the visible property of the column.
dataGridView1.Columns(0).Visible = False
Worked perfectly by doing the following:
dataGridView1.Columns[0].Visible = false; instead of () needed to use [].
Thanks. Now just to name my Columns!
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Solution:
dataGridView1.Columns[0].Visible = false;
dataGridView1.Columns[1].HeaderText = "First Name";
Is this the best way to do it? Any downsides?
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If someone added another column, or insert a column before the firstcolumn, the datagridview will display wrongly. Generally I will define the columns to be displayed and their order, instead of hiding the columns that I do not want to display.
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Define only the columns that you want to display in the datagridview:
this.dataGridView.AutoGenerateColumns = false;
this.dataGridView.Columns.Clear();
this.dataGridView.Columns.AddRange(GetGridViewColumns());
private DataGridViewColumn[] GetGridViewColumns()
{
DataGridViewTextBoxColumn id = new DataGridViewTextBoxColumn();
id .DataPropertyName = "ID";
id .HeaderText = "ID";
id .Name = "ID";
id .SortMode = DataGridViewColumnSortMode.Automatic;
id .ReadOnly = true;
id .Width = 100;
id .DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft;
id .DefaultCellStyle.Format = "";
DataGridViewTextBoxColumn name= new DataGridViewTextBoxColumn();
name.DataPropertyName = "Name";
name.HeaderText = "Name";
name.Name = "Name";
name.SortMode = DataGridViewColumnSortMode.Automatic;
name.ReadOnly = true;
name.Width = 100;
name.DefaultCellStyle.Alignment = DataGridViewContentAlignment.MiddleLeft;
name.DefaultCellStyle.Format = "";
return new DataGridViewColumn[] { id, name };
}
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Thank you so much this is perfect. Just what I am looking for! Codeproject is such a great community!
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