I want count uniques along with value in array?

Question

I have 6 numbers in array .

string[] list = { "1", "1", "2","2","1","3" };

I want result like this. please help.

"1" = 3
"2" = 2
"3" = 1

Make a loop through the list and count letters you want. It's the simplest and the most natural way. — King King, Apr 11 '13 at 13:23

score 3 · Accepted Answer · answered Apr 11 '13 at 13:12

3

var itemCounts = list.GroupBy(l => l)
                     .Select(g => new { key = g.Key, count = g.Count()});

answered Apr 11 '13 at 13:12

paul

Nice, I had the same solution but you were faster :) – L-Four Apr 11 '13 at 13:22
thanks sir , please one huge help for me now , if i want get first 1 Max(count) from itemCounts along with key how to get please . – Saqi Apr 11 '13 at 13:29
1

`var topItem = itemCounts.OrderByDescending(m => m.count).Take(1);` – paul Apr 11 '13 at 13:31

score 1 · Answer 2 · answered Apr 11 '13 at 13:19

1

Assuming your numbers in SearchArray >0. Here is an alternative approach

You can also write a function 1) find Max - One Loop

  for( int i=0;i<searchArray.length;i++){
    if (searchArray[i]>max) max=searchArray[i];
  }

2) Initialize an Array[Max+1]= 0

3) Loop thru each item and increment the size in Array

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

     Array[searchArray[i]]++;
  }

answered Apr 11 '13 at 13:19

aked

Why would one use this `O(n*n)` algorithm while Linq is shorter and **faster** – I4V Apr 11 '13 at 13:24
1

I4V, do you really understand how Linq work? I don't think using loop is slower. Loop is always the basic of everything related to processing list and IEnumerable stuff. – King King Apr 11 '13 at 13:25
@I4V i think this is not N^2 this is N+N right 2N so in Big O notation this N order right ? – aked Apr 11 '13 at 13:25
@KingKing, I guess *you* don't understand it. `GroupBy` uses HashSet internally which has `O(1)` complexity. @simplecoder, I though you used two nested loops, so forget my comment. – I4V Apr 11 '13 at 13:28
@I4V OK, if so, we can use HashSet for our collection and use loop outside without linq, however that's just an idea, I still love LINQ so much, but I also love the so-called loop in programming. :) – King King Apr 11 '13 at 13:31
1

@KingKing of course,.. – I4V Apr 11 '13 at 13:34

2 Answers2