# Group numbers via digits frequency

• A list of numbers are given. We need to find the total number of groups in which the digits of each number have same frequency.
For example if numbers are:
1
10
303
330

There are 3 groups:
G1={1}has one 1.
G2={10} has one 1 and one 0.
G3={330, 303} has one 0 and two 3s.

• G2={3} has one 3.

I didn't see `3` in the list of numbers?

• @1337c0d3r Edited. Thanks!

• A variation of Group Anagrams?

Just sort the digits of each number and de-dupe them.

• ``````            int re=0;
int[] nums = { 0,10,303,330};
HashSet<string> set = new HashSet<string>();
foreach (int var in nums)
{
string s = var.ToString();
char[] c = s.ToArray();
Array.Sort(c);
string cur=new string(c);
if (!set.Contains(cur))
{
re++;
}

}
Console.Write(re);
``````

• ``````        static void Main(string[] args)
{
var input = new[] {1, 10, 303, 330};
var groups = new Dictionary<string, string>();

foreach (var i in input)
{
var key = string.Join("", i.ToString().OrderBy(c => c));
if (!groups.ContainsKey(key))
{
groups[key] = i.ToString();
}
else
{
groups[key] += \$",{i}";
}
}

foreach (var g in groups)
{
Console.WriteLine(\$"{g.Key} :: {g.Value}");
}
}
``````

• Does 123 also fit into Group3?

• @nishanth Groups are defined by the count of each digit, not the length of the number. 123 has one 1, one 2, and one 3, thus it would not fit Group 3 in the example given by the OP.

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