how to write a program for all possible combination of array

Hi,

Found this code from net. Not sure about the performance with large arrays. Just give it a try -

protected void Page_Load(object sender, EventArgs e)

{

int[] myarr = new[] { 1, 2, 3, 4 };

string[] responsearr = Getdata(myarr);

}

public string[] Getdata(int[] arr)

{

return Combination(string.Join("", arr));

}

public string[] Combination(string str)

{

if (string.IsNullOrEmpty(str))

throw new ArgumentException("Invalid input");

if (str.Length == 1)

return new string[] { str };

// read the last character

char c = str[str.Length - 1];

// apart from the last character send remaining string for further processing

string[] returnArray = Combination(str.Substring(0, str.Length - 1));

// List to keep final string combinations

List finalArray = new List();

// add whatever is coming from the previous routine

foreach (string s in returnArray)

finalArray.Add(s);

// take the last character

finalArray.Add(c.ToString());

// take the combination between the last char and the returning strings from the previous routine

foreach (string s in returnArray)

finalArray.Add(s + c);

return finalArray.ToArray();

}

You will get the desired data as array in "responsearr".

Please also take a look at this article -

http://www.codeproject.com/Articles/26050/Permutations-Combinations-and-Variations-using-C-G

2 Replies

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Midhun Tp10y ago
Hi,

Found this code from net. Not sure about the performance with large arrays. Just give it a try -
protected void Page_Load(object sender, EventArgs e)
{
int[] myarr = new[] { 1, 2, 3, 4 };
string[] responsearr = Getdata(myarr);
}
public string[] Getdata(int[] arr)
{
return Combination(string.Join("", arr));
}
public string[] Combination(string str)
{
if (string.IsNullOrEmpty(str))
throw new ArgumentException("Invalid input");
if (str.Length == 1)
return new string[] { str };
// read the last character
char c = str[str.Length - 1];
// apart from the last character send remaining string for further processing
string[] returnArray = Combination(str.Substring(0, str.Length - 1));
// List to keep final string combinations
List finalArray = new List();
// add whatever is coming from the previous routine
foreach (string s in returnArray)
finalArray.Add(s);
// take the last character
finalArray.Add(c.ToString());
// take the combination between the last char and the returning strings from the previous routine
foreach (string s in returnArray)
finalArray.Add(s + c);
return finalArray.ToArray();
}

You will get the desired data as array in "responsearr".

Please also take a look at this article -
http://www.codeproject.com/Articles/26050/Permutations-Combinations-and-Variations-using-C-G
Rajeesh Menoth10y ago
Hi,

Similar Threads :

http://stackoverflow.com/questions/1272828/getting-all-the-combinations-in-an-array

http://stackoverflow.com/questions/1952153/what-is-the-best-way-to-find-all-combinations-of-items-in-an-array