C# Algorithm: Given a string, find the first non-repeating character in it

Posted on 2013-12-12
Last Modified: 2013-12-12
Can any one help with this please?
Question by:Techsavy
  • 2

Accepted Solution

virtuadept earned 500 total points
ID: 39714881
This solution was found here:

LINQ version:

using System.Linq;
string str = "abcabda";
char result = str.FirstOrDefault(ch => str.IndexOf(ch) == str.LastIndexOf(ch));

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Non LINQ version:

  for (int index = 0; index < str.Length; index++)
        if (str.LastIndexOf(str[index]) == str.IndexOf(str[index]))
            result = str[index];

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Author Closing Comment

ID: 39714929
Very Easy to Follow

Expert Comment

ID: 39715002
I like the one-liner LINQ solution if you have a recent C#.NET, but for older versions of C# you may need to use the looping solution. Enjoy!

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