Without using a data structure, display whether each character in a string is unique

Question

Without using a data structure, I need to display whether each character in a string is unique or not.

I wrote the code and it works for paa but it doesn't work for pak.

var String = "paa"
//var String = "pak"
var splittedString = String.split();

for(i = 0; i < splittedString.length; i++) {

    if(splittedString[i] === splittedString[i+ 1] || 
            splittedString[i+1] === splittedString[i + 2]) {
        console.log("not unique string");
    } else {
        console.log("its an unique string")
    }
}

Your code uses a data structure, I'm sorry to say. What is the point of that restriction? — Pointy, Apr 21 '17 at 16:11
There is a lot of questions about it. For example: http://stackoverflow.com/questions/12870489/regex-to-match-a-word-with-unique-non-repeating-characters — dagatsoin, Apr 21 '17 at 16:11
Possible duplicate of [Javascript: Determine if all characters in a string are unique and if not, delete duplicate characters](http://stackoverflow.com/questions/17285948/javascript-determine-if-all-characters-in-a-string-are-unique-and-if-not-delet) — Mayank Shukla, Apr 21 '17 at 16:12
Why is this tagged `reactjs`, `jquery`, `angular`, and `backbone.js`? It has nothing to do with those libraries / frameworks. — Todd Chaffee, Apr 21 '17 at 16:18

score 1 · Answer 1 · answered May 09 '17 at 17:56

It is clearly stated in the problem don't need to use the data structure. I saw above answers using an array. I try to solve this issue in C#. Let me know if you have any feedback.

public bool IsUnique(string text)
{
    if (text.Length > 256) return false;

    for (var indx = 0; indx < text.Length; indx++)
    {
        for (var jndx = indx + 1; jndx < text.Length; jndx++)
        {
            // compare character 
            if (text.Substring(indx, 1) == text.Substring(jndx, 1) )
            {
                return false;
            }
        }
    }

    return true;
}

score 0 · Answer 2 · answered Apr 21 '17 at 16:18

0

First you sort the characters in the string and then compare each one to the next.
The program with regex may look like below

var str = "alphabet";
var sstr = str.split('').sort().join('');
var result = /(.)\1/.test(sstr);
console.log(sstr + " has dups: " + result)

answered Apr 21 '17 at 16:18

MaxZoom

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`aabehlpt has dups: true`, nice output :P – Emile Bergeron Apr 21 '17 at 16:26
@TylerSebastian `sstr` is a sorted string. Regex description is explained [here](https://regex101.com/r/Af5M6p/2). – MaxZoom Apr 21 '17 at 16:31
var String = "paa" //var String = "pak" var splittedString = String.split().sort(); for(i=0; i – Apr 21 '17 at 16:42

score 0 · Accepted Answer · answered Apr 21 '17 at 17:05

0

Just to show the needed change in your code, plus nice output as per Emile's request:

var str = "palace";
//var str = "pak";
var splittedString = str.split('');

for (i=0; i<splittedString.length; i++) {
  var c = splittedString[i];
  var unique = true;
  for (j=0; j <splittedString.length; j++) {
    if (i==j) continue;
    if (c === splittedString[j]) {
      unique = false;
      break;
    }
  }
  console.log("'" + c + "' is" + (unique ? '': ' not') + " unique character");
}

answered Apr 21 '17 at 17:05

MaxZoom

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var String = "paa" //var String = "pak" var splittedString = String.split().sort(); for(i=0; i – Apr 21 '17 at 18:28
hey I used your logic, but still not working...can you tell me why its not working... – Apr 21 '17 at 18:29
updated but still doesn't work ---> var String = "paa" //var String = "pak" var splittedString = String.split() console.log("outside outer loop"); for(i=0; i – Apr 21 '17 at 18:49
1

Your split method should define some character separator – MaxZoom Apr 21 '17 at 19:21
still not working ---> var wholeWord = "paa"; //var String = "pak" var splittedString = wholeWord.split(''); for(i=0; i – Apr 21 '17 at 19:50
hey thanks for your help I got it working https://jsfiddle.net/at661zsu/ – Apr 21 '17 at 20:10
have one more doubt...is it possible to achieve without using data structure since split will return in array right...since array is a data structure right?? – Apr 21 '17 at 20:22
1

Yes, glad you have it resolved. Please up-vote the answer(s) (if applicable) – MaxZoom Apr 21 '17 at 20:38
1

You can try [String.charAt(..)](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/charAt) instead of array`[index]` notation. – MaxZoom Apr 21 '17 at 21:16
I tried using charAt but its not working as expected, can you let me know what is the problem https://jsfiddle.net/at661zsu/1/ – Apr 22 '17 at 00:34
hello can you help me with this one http://stackoverflow.com/questions/43600110/minimise-the-code-since-i-am-using-the-same-code-only-the-content-in-p-tags-chan – Apr 25 '17 at 03:35

Without using a data structure, display whether each character in a string is unique

3 Answers3